IODP, International Ocean Discovery Program, ECORD Expedition 364, Apr-May 2016
If the rock that hit the Earth 66 million years ago had been just a little later, or a little earlier, we might not be here talking about it.
“They illustrate what happened in the seconds and hours after the impact, revealing that had the huge asteroid struck the Earth a moment earlier, or later, the destruction might not have been total for the dinosaurs. And if they still roamed the world, we humans may never have come to rule the planet.” — BBC Two — The Day the Dinosaurs Died
I was once almost eaten by a shark in the warm waters off Chicxulub. It was 1972 and I was on holiday in Mexico. We were spending a week in the Yucatan. After leaving Merida our concierge, driver, cook, and friend took us to his mother-in-law’s summer home on the beaches of Chicxulub. My spanish is not good and I thought we had rented the little cabin/hut in the back of the beach front property. “No, no esa cosa pequeña … esa casa grande!”
It was awesome. The sand, the art, the cool tiles, the warm sea … and it seemed that we had it all to ourselves. After a few days of our fabulous holiday, my partner had to go into town about the car rental, but despite the warnings I’d heard about swimming with a partner, I couldn’t stay out of the ocean and I went into those waves anyways. I’m splashing around about 100 feet off shore when I noticed a small boy on the beach, jumping up and down, waving, and yelling at me … “hola!” “What’s that you’re saying?” I swam back to shore but he ran away, up the beach, toward the nearby small town of Chicxulub.
My partner and I regularly walked into Chicxulub in the evening, where we ate street food and soaked up the ambiance. That night, as we walked along the beach, we could see there was quite a happening on the town dock, boats and trucks, lots of people, lights and action. It wasn’t long before we were at the scene and had it figured out. They were hauling a huge dead shark onto the dock. This was no baby shark. It was gianormous. Indeed I’m convinced it was the inspiration for the movie “Jaws” which was released only a few years later. When people talked about the movie I thought, that was nothing! You should have seen the monster we saw in Chicxulub!
Anyways, we left the dock and walked the short distance to a large restaurant we had planned to eat at on our last day in the Yucatan. We enter, and who is the first person I see? The boy who was on the beach that morning! He seemed really happy to see me and soon his Dad was ushering us to a table where he handed us a couple of menus. And there, on the menu, was the word the boy had been yelling at me that afternoon. Hola! tiburón! tiburón! tiburón! “
Then, in 1980, the father-and-son team of scientists Luis and Walter Alvarez, suggested the hypothesis that the mass extinction of the dinosaurs was caused by the impact of a large asteroid hitting Earth. And last year, ECORD, the European Consortium for Ocean Research Drilling, launched an expedition to drill core from the crater peak of that event. Here is the web page.
Notes:
Created 2001, Updated: Feb 2007, last update (code clean) Apr 2017
>20 km The formation of impact craters as small as 20 km could produce light reductions and temperature disruptions similar to a nuclear winter. Such impacts occur on Earth with a frequency of two or three every million years.
I began this Earth Crater project back in the late 90’s, pre-google. The html has had some updates. 😉 And, most awesomely, there are 40 more earth crater discoveries since those days. Today, (Apr 2017) do find your details about earth impactors at
The ways in which men came into the knowledge of things celestial appears to me almost as marvelous as the nature of these things themselves.
— Johannes Kepler
The impact of comets has profoundly influenced the story of life.
— Gene Shoemaker
MAP - WMAP : NASA Explorer Mission measuring the temperature of the cosmic background radiation over the full sky,
remnant heat of the Big Bang provides answers to fundamental questions about the origin and fate of our universe.
http://map.gsfc.nasa.gov/index.htm
Stellarium: free GPL software which renders realistic skies in real time
http://www.stellarium.org
Lat and Long for Victoria, BC : Latitude 48° 25' Longitude 123° 21'
Moving Stars and Earth for Water event is a World premiere artistic event which will be presented via Live Webcast on ONE DROP’s website (http://www.onedrop.org) on October 9, at 8:00 p.m. EDT. (That’s 5:00 p.m. PDT)
After a year training and paying the $35 million ticket price, Guy Laliberte, first Canadian Space Tourist and Founder/CEO of Cirque du Soleil, launched from Baikonur to the Internationl Space Station on September 30. He arrived at ISS today, October 30, for two weeks aboard the orbiting station.
At around 7:17 on the morning of June 30, 1908, a man based at the trading post at Vanavara in Siberia is sitting on his front porch. In a moment, 40 miles from the center of an immense blast of unknown origin, he will be hurled from his chair and the heat will be so intense he will feel as though his shirt is on fire. The man at the trading post, and others in a largely uninhabited region of Siberia, near the Podkamennaya Tunguska River, are to be accidental eyewitnesses to cosmological history.
The model of the JWST is on display in Washington DC. The US space agency Nasa has unveiled a model of a space telescope that scientists say will be able to see to the farthest reaches of the Universe. The James Webb Space Telescope (JWST) is intended to replace the aging Hubble telescope. It will be larger than its predecessor, sit farther from Earth and have a giant mirror to enable it to see more. Officials said the JWST – named after a former Nasa administrator – was on course for a launch in June 2013.
Large galaxy clusters are the universe’s metropolises, and for years many astronomers have focused their attention on the crowded “downtowns.” However, a new map of some of the largest ancient galactic cities shows that much of the “action” is happening in the cosmic suburbs. Keep on reading!
Report Reveals Likely Causes of Mars Spacecraft Loss
Mars Global Surveyor
WASHINGTON – After studying Mars four times as long as originally planned, NASA’s Mars Global Surveyor orbiter appears to have succumbed to battery failure caused by a complex sequence of events involving the onboard computer memory and ground commands.
The causes were released today in a preliminary report by an internal review board. The board was formed to look more in-depth into why NASA’s Mars Global Surveyor went silent in November 2006 and recommend any processes or procedures that could increase safety for other spacecraft.
Mars Global Surveyor last communicated with Earth on Nov. 2, 2006. Within 11 hours, depleted batteries likely left the spacecraft unable to control its orientation.
Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
NEWS RELEASE: 2007-040 April 13, 2007
“The loss of the spacecraft was the result of a series of events linked to a computer error made five months before the likely battery failure,” said board Chairperson Dolly Perkins, deputy director-technical of NASA Goddard Space Flight Center, Greenbelt, Md.
On Nov. 2, after the spacecraft was ordered to perform a routine adjustment of its solar panels, the spacecraft reported a series of alarms, but indicated that it had stabilized. That was its final transmission. Subsequently, the spacecraft reoriented to an angle that exposed one of two batteries carried on the spacecraft to direct sunlight. This caused the battery to overheat and ultimately led to the depletion of both batteries. Incorrect antenna pointing prevented the orbiter from telling controllers its status, and its programmed safety response did not include making sure the spacecraft orientation was thermally safe.
The board also concluded that the Mars Global Surveyor team followed existing procedures, but that procedures were insufficient to catch the errors that occurred. The board is finalizing recommendations to apply to other missions, such as conducting more thorough reviews of all non-routine changes to stored data before they are uploaded and to evaluate spacecraft contingency modes for risks of overheating.
“We are making an end-to-end review of all our missions to be sure that we apply the lessons learned from Mars Global Surveyor to all our ongoing missions,” said Fuk Li, Mars Exploration Program manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
Mars Global Surveyor, launched in 1996, operated longer at Mars than any other spacecraft in history, and for more than four times as long as the prime mission originally planned. The spacecraft returned detailed information that has overhauled understanding about Mars. Major findings include dramatic evidence that water still flows in short bursts down hillside gullies, and identification of deposits of water-related minerals leading to selection of a Mars rover landing site.
The Jet Propulsion Laboratory, Pasadena, Calif., manages Mars Global Surveyor for NASA’s Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft.
Information about the Mars Global Surveyor mission, including the preliminary report from the process review board and a list of some important discoveries by the mission, is available on the Internet at:
— Beth A. Biller is part of an international team of astronomers trying to tease out images of planets around young stars by removing the distortions caused by Earth’s atmosphere.
Extrasolar planets are extremely faint targets to begin with, and an atmospheric effect known as “speckling” has thwarted most previous attempts to observe them directly. Using instruments installed at the Very Large Telescope in Chile, Biller’s team has constructed some of the highest contrast images every obtained of substellar objects.
Her work is also helping determine requirements for NASA’s Terrestrial Planet Finder, a future mission that will directly observe and characterize habitable planets around nearby stars. Currently a doctoral candidate at the University of Arizona, she presented her research in an oral session at this year’s winter meeting of the American Astronomical Society. She is a native of the Washington, D.C., area.
MAUNA KEA (February 4, 2005) Astronomers using the Keck I telescope in Hawaii are learning much more about a strange, thermal ” hot spot” on Saturn that is located at the tip of the planet’s south pole. In what the team is calling the sharpest thermal views of Saturn ever taken from the ground, the new set of infrared images suggests a warm polar vortex at Saturn’s south pole — the first to ever be discovered in the solar system. This warm polar cap is home to a distinct compact hot spot, believed to contain the highest measured temperatures on Saturn. A paper announcing the results appears in the Feb. 4th issue of “Science.”
A ” polar vortex” is a persistent, large-scale weather pattern, likened to a jet stream on Earth that occurs in the upper atmosphere. On Earth, the Arctic Polar Vortex is typically located over eastern North America in Canada and plunges cold arctic air to the Northern Plains in the United States. Earth’s Antarctic Polar Vortex, centered over Antarctica,is responsible for trapping air and creating unusual chemistry, such as the effects that create the ” ozone hole.” Polar vortices are found on Earth, Jupiter, Mars and Venus, and are colder than their surroundings. But new images from the W. M. Keck Observatory show the first evidence of a polar vortex at much warmer temperatures. And the warmer, compact region at the pole itself is quite unusual.
” There is nothing like this compact warm cap in the Earth’s atmosphere,” aid Dr. Glenn S. Orton, of the Jet Propulsion Laboratory in Pasadena and lead author of the paper describing the results. ” Meteorologists have detected sudden warming of the pole, but on Earth, this effect is very short-term. This phenomenon on Saturn is longer-lived because we’ve been seeing hints of it in our data for at least two years.”
The puzzle isn’t that Saturn’s south pole is warm; after all, it has been exposed to 15 years of continuous sunlight, having just reached its summer Solstice in late 2002. But both the distinct boundary of a warm polar vortex some 30 degrees latitude from the southern pole and a very hot “tip” right at the pole were completely unexpected.
“ If the increased southern temperatures are solely the result of seasonality, then the temperature should increase gradually with increasing latitude, but it doesn’t,” added Dr. Orton. “ We see that the temperature increases abruptly by several degrees near 70 degrees south and again at 87 degrees south.”
The abrupt temperature changes may be caused by a concentration of sunlight-absorbing particulates in the upper atmosphere which trap in heat at the stratosphere. This theory explains why the hot spot appears dark in visible light and contains the highest measured temperatures on the planet. However, this alone does not explain why the particles themselves are constrained to the general southern part of Saturn and particularly to a compact area near the tip of Saturn’s south pole. Forced downwelling of relatively dry air would explain this effect, which is consistent with other observations taken of the tropospheric clouds, but more observations are needed.
More details may be forthcoming from an infrared spectrometer on the joint NASA/ESA Cassini mission which is currently orbiting Saturn. The Composite Infrared Spectrometer (CIRS) measures continuous spectral information spanning the same wavelengths as the Keck observations, but the two experiments are expected to complement each other. Between March and May in 2005, the CIRS instrument on Cassini will be able to look at the south polar region in detail for the first time. The discovery of the hot spot at Saturn’s south pole has prompted the CIRS science team, one of whom is Dr. Orton, to spend more time looking at this area.
” One of the obvious questions is whether Saturn’s north pole is anomalously cold and whether a cold polar vortex has been established there,” added Dr. Orton. “This is a question that can only be answered by the Cassini’s CIRS experiment in the near term, as this region can not be seen from Earth using ground-based instruments.”
Observations of Saturn were taken in the imaging mode of the Keck Long Wavelength Spectrometer (LWS) on February 4, 2004. Images were obtained at 8.00 microns, which is sensitive to stratospheric methane emission, and also at 17.65 and 24.5 microns, which is sensitive to temperatures at various layers in Saturn’s upper troposphere. The full image of the planet was mosaicked from many sets of individual exposures.
Future work observing Saturn will include more high-resolution thermal imaging of Saturn, particularly due to the fact that the larger polar vortex region may change in the next few years. The team has also discovered other phenomena which could be time dependent and are best characterized by imaging instruments at Keck, such as a series of east-west temperature oscillations, most prominently near 30 degrees south. These effects appear to be unrelated to anything in Saturn’s relatively featureless visible cloud system, but the variability is reminiscent of east-west temperature waves in Jupiter which move very slowly compared to the rapid jets tracked by cloud motions.
Funding for this research was provided by NASA’s Office of Space Sciences and Applications, Planetary Astronomy Discipline, and the NASA Cassini project. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C.
The W.M. Keck Observatory is operated by the California Association for Research in Astronomy, a non-profit scientific partnership of the California Institute of Technology, the University of California, and NASA.
Canada will land on the surface of another planet for the first time when Phoenix, an international mission to Mars, touches down in 2008. Slated for launch on August 3, 2007, Phoenix will dig beneath Mars’s surface in search of ice – in search of life. Two Canadian instruments on board Phoenix will study Mars’s weather and climate to pave the way for future exploration missions.
Join the Canadian Space Agency’s Dr. Victoria Hipkin at the H.R. MacMillan Science Centre at 7:30 p.m. on Friday, April 20, 2007, for a special presentation on this exciting mission. Try a space science experiment at the Canadian Space Agency’s information booth. Learn everything you ever wanted to know about the Red Planet, and why the world’s scientists want to explore it.
The conquest of space has been a dream of humans for centuries. Only in the last five decades however, have we had the technology to explore the cosmos. Until recently, this technology has been limited to only a few countries, including the United States, which leads the world. Lately though, Canada, too, has been gaining a foothold in space science.
Canadian scientists and engineers have made a series of important contributions to space missions, like Radarsat, the robotic Canadarms for the space shuttle and the International Space Station, and the MOST space telescope, just to name a few. Now, under the auspices of its own space agency, Canada is partnering with other countries to help explore the Red Planet. In its latest project, the Canadian Space Agency (CSA) is collaborating with NASA on its next Mars lander, called Phoenix, scheduled for launch in 2007. Hopes are high that the Canadian maple leaf will soon be seen on Mars.
As the Mars Program lead at CSA, Dr. Alain Berinstain (pictured above) acts as the link between the scientific community and research and development teams in government and industry. He is also responsible for science missions that explore the planets (including Mars), Mars-analog sites on Earth, and astronomy missions. Berinstain has a Bachelor’s degree in chemistry and biochemistry and a doctorate in chemistry, specializing in the effects of radiation on biological systems. As adjunct professor at University of Guelph, he also conducts research into environmental controls systems for greenhouses in extreme environments. We interviewed him via telephone last week.
NASA’s Spitzer First To Crack Open Light of Faraway Worlds
For Release: February 21, 2007
Spitzer captures light from planets outside our solar system
NASA’s Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify signatures of molecules in their atmospheres. The landmark achievement is a significant step toward being able to detect possible life on rocky exoplanets and comes years before astronomers had anticipated.
“This is an amazing surprise,” said Spitzer project scientist Dr. Michael Werner of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We had no idea when we designed Spitzer that it would make such a dramatic step in characterizing exoplanets.”
Spitzer, a space-based infrared telescope, obtained the detailed data, called spectra, for two different gas exoplanets. Called HD 209458b and HD 189733b, these so-called “hot Jupiters” are, like Jupiter, made of gas, but orbit much closer to their suns.
They’re the Solar TerrEstrial RElations Observatories (STEREO… get it?), and they were lofted into orbit on October 25 http://www.universetoday.com/2007/01/25/first-images-of-the-sun-from-stereo/
ABLATION: Removal of material by heating and vaporization as a meteorite passes through Earth’s atmosphere.
ACCRETION:
ACHONDRITE: A class of stony meteorite formed by an igneous process; the lack of chondrules.
ALBEDO: the fraction of incident radiation, light, that is reflected by a surface. 1.0 = white, 0.0 = black
ALBEDO FEATURE: A dark or light marking on the surface of an object that may not be a geological or topographical feature.
ALLOCTHONOUS: Material that is formed or introduced from somewhere other than the place it is presently found. In impact cratering this may refer to the fragmented rock thrown out of the crater during its formation that either falls back to partly fill the crater or blankets it’s outer flanks after the impact event.
AMOR ASTEROIDS: A ‘Near Earth Asteroid’ which has a perihelion distance just beyond Earth orbit. 1.017 AU and 1.3 AU. Designation List
ANTIPODAL POINT: the point that is directly on the opposite side of the planet.
APHELION: the point in its orbit where a planet is farthest from the Sun.
APOLLO ASTEROIDS: A ‘Near Earth Asteroid’ which has a semimajor axes greater than 1.0 AU and perihelion distances less than 1.017 AU. Designation List
ASTEROID BELT: Between the orbits of Mars and Jupiter where most asteroids are located.
ASTEROID NUMBER: asteroids are assigned a serial number when they are discovered.
ASTEROIDS are small, mostly rocky bodies orbiting the Sun. Asteroids range in size from 1000 kilometers in orbit the Sun between Mars and Jupiter and are the source of most meteorites. They are classified into a number of types according to their spectra (and hence their chemical composition) and albedo (There are actually several classification schemes in use today.) There are also a dozen or so other rare types.
C-type, includes more than 75% of known asteroids: extremely dark (albedo 0.03); similar to carbonaceous chondrite meteorites; approximately the same chemical composition as the Sun minus hydrogen, helium, and other volatiles;
S-type, 17%: relatively bright (albedo .10-.22); metallic nickel-iron mixed with iron and magnesium silicates;
M-type, most of the rest: bright (albedo .10-.18); pure nickel-iron.
ASTROBIOLOGY: Study of the origin, distribution, and destiny of life in the universe.
ASTROBLEME: literally means “star wound” and refers to an ancient, eroded, meteoritic crater.
ASTRONOMICAL UNIT: (AU) 149,597,870.691 km; the average distance from the Earth to the Sun.
ATEN : asteroids that are always closer to the Sun than the Earth is; they have a period shorter than 1 year (the semi-major axis is smaller than Earth’s). Designation List
– b –
BARRINGER CRATER: also known as Meteor Crater, Arizona, USA.
BASALT: common volcanic igneous rock
BOLIDE: a fireball that produces a sonic boom
BRECCIA: Rock consisting of angular, coarse fragments embedded in a fine-grained matrix.
– c –
CALDERA: a crater formed by an explosion or by a collapsed volcanic vent
CARBON: An element with atomic number 6; symbol: C. Carbon is one of the four elements essential for life. (The others are hydrogen, oxygen, and nitrogen.)
CARBONATE: A compound containing carbon and oxygen.
CATACLASTIC: A texture found in metamorphic rocks in which brittle minerals have been broken, crushed, and flattened during shearing.
CATENA: A chain of craters.
CAVUS: Hollow, irregular depression.
CENTAURS : A diverse group of rocks in the outer solar system that displays episodic cometary behavior and eccentric orbits. Centaurs are objects that probably came from the Kuiper belt.(also a class of rocket). The plot of the outer solar system.
CENTRAL PEAK: The exposed core of uplifted rocks in complex meteorite impact craters. The central peak material typically shows evidence of intense fracturing, faulting, and shock metamorphism.
CERES: The largest and first discovered (1801) asteroid in the Asteroid Belt.
CHAOS: distinctive area of broken terrain.
CHICXULUB CRATER: The submerged crater at the tip of the Yucatán Peninsula is an impact crater that dates from 65 million years ago. It is 120 miles wide and 1 mile deep. It is probably the site of the K-T meteorite or comet impact that caused the extinction of the dinosaurs and other groups of organisms.
CHONDRITE: A common type of meteorite that contains chondrules (see definition below). Chondrites come from asteroids that did not melt when formed and are designated as H, L, LL, E, or C depending on chemical compositions. The H, L, and LL types are called ordinary chondrites. The L chondrites are composed of silicate minerals (mostly olivine and pyroxene, but feldspar as well), metallic nickel-iron, and iron sulfide (called troilite). Most L chondrites are severely shocked-damaged, probably by a large impact on the asteroid in which they formed. The C (or carbonaceous) chondrites are the most primitive meteorites. They contain water-bearing minerals and carbon Compounds including a variety of organic molecules such as amino acids.
CHONDRULE : Roughly spherical objects found in a type of meteorite called chondrites. Most chondrules are 0.5 to 2 millimeters in size and are composed of olivine and pyroxene, with smaller amounts of glass and iron-nickel metal. The shapes of the mineral grains in them indicate that chondrules were once molten droplets floating freely in space.
COMA: The dust and gas surrounding an active comet’s nucleus
COMET: A medium-sized icy object orbiting the Sun; smaller than a planet. It is made up of a nucleus (solid, frozen ice, gas and dust), a gaseous coma (water vapor, CO2, and other gasses) and a tail (dust and ionized gasses). Because of the force of the solar wind its long tail of gas and dust always points away from the sun, The tail can be up to 250 million km long. Comets are only visible when they’re near the sun in their highly eccentric orbits.
COMMENSURATE ORBITS: Asteroid orbits whose periods are simple multiples or fractions of Jupiter’s orbital period.
COMPLEX IMPACT CRATER: A large crater with a single or many peaks in the middle of the crater. Examples are found on the Moon and on Earth.
COSMIC DUST: Microscopic silicate or iron particles. IPD’s (Interplanetary dust particles) can collect in buried mud, the atmosphere, or in space. Smaller than the dust-like particles we see burning up during a meteor shower. Cosmic Dust originates withing comets and asteroids, and perhaps in the solar nebula. The dust may be carbon-rich, and may have provided an source of organic material for early Earth.
COSMIC RAY EXPOSURE AGE: An age determined by the presence of specific isotopes produced by cosmic ray bombardment.
COSMIC VELOCITY: The velocity of an orbiting body in space.
CRATER: Bowl shaped depression caused by impact or a depression around a volcanic vent.
CRATER RAYS: Lines of ejecta radiating from a crater.
CRATON : The stable portions of continents composed of shield areas and platform sediments. Typically cratons are bounded by tectonically active regions characterized by uplift, faulting, and volcanic activity.
CRETACEOUS PERIOD: A geological term denoting the interval of Earth history beginning around 144 million years ago and ending 66 million years ago with the Chixalub impact and the demise of the age of dinosaurs.
CRYSTALLINE : – Rock types made up of crystals or crystal fragments, such as metamorphic rocks that recrystallized in high-temperature or pressure environments, or igneous rocks that formed from cooling of a melt. Crystallization; the formation of minerals with an ordered atomic crystalline structure.
CRYSTAL LATTICE: An orderly arrangement of atoms in a mineral.
– d –
DENSITY: measured in grams per cubic centimeter (or kilograms per liter); the density of water is 1.0; iron is 7.9; lead is 11.3.
DIAPLECTIC GLASS: A natural glass formed by shock pressure from any of several minerals without melting. It is found only in association with meteorite impact craters.
DIFFERENTIATION: Chemical zonation caused by differences in the densities of minerals; heavy materials sink, less dense materials float.
DINOSAURS: large reptiles that lived until 65 million years ago. Most probably wiped out by an impact.
DISASTER: From the greek “dis” and “aster”, the opposite of a sprinkle of light (stars).
DISTRIBUTION ELLIPSE: An area over several kms in which meteorites tend to fall with the more massive fragments at one end.
– e –
EARTH GRAZER: A meteoroid (or other space debris) that enters the Earth’s atmosphere and disintegrates, traveling nearly parallel to Earth’s surface
ECCENTRICITY: The astronomical measurement describing an orbit’s deviation from the circular.
EJECTA: Material thrown out from and deposited around an impact crater.
ELLIPSE: oval. the orbits of the planets are ellipses, not circles.
ENERGY: The capacity for doing work. Energy can change from one form (heat, chemical, nuclear, potential energy) into another but is always conserved.
EON: Two or more geological Eras form an Eon, which is the largest division of geological time, lasting hundreds of millions of years.
EPOCH: A division of a geologic period; it is the smallest division of geologic time, lasting several million years.
EXPONENTIAL NOTATION: “1.23e4” means “1.23 times 10 to the fourth power” or 12,300; “5.67e-8” means “5.67 divided by 10 to the eighth power” or 0.0000000567.
– f –
FACULA: Bright spot. For example, the Memphis Facula around bright region of Ganymede, a moon of Jupiter.
FALLS: Rare, a rock found as the result of an ‘observed’ meteorite impact.
FINDS : The majority of meteorites are recorded as finds, those specimens which were not observed to fall.
FIREBALL: a meteor brighter than magnitude -3 caused by millimeter-sized (or bigger) meteoroids disintegrating in the atmosphere.
FISSURE: a narrow opening or crack of considerable length and depth.
FRACTIONATION: Fractional crystallization: a process in which minerals crystallize out of a magma at specific temperatures, thereby changing the composition of the magma.
FRAGMENT:
FUSION CRUST:
– g –
GEOCENTRIC DISTANCE: The distance from Earth.
GEOLOGIST: Scientist who studies Earth, its materials, the physical and chemical changes that occur on the surface and in the interior, and the history of the planet and its life forms. Planetary geologists extend their studies to the Moon, planets, and other solid bodies in the Solar System.
GEGENSCHEIN: Faint, diffuse, glowing region on the ecliptic opposite of the Sun produced by IDP’s (interplanetary dust particles)
GIANT IMPACT THEORY: An explanation for the origin of the Moon from Earth debris which collected in space after a projectile the size of planet Mars smashed into a growing Earth.
– h –
HEXAHEDRITE: An iron meteorite containing less than 5 percent nickel.
HIGH-PRESSURE MINERAL PHASES: Mineral forms that are stable only at the extremely high pressures typical of Earth’s deep interior but not its surface. Such pressures are generated instantaneously during meteorite impact. For example, stishovite is the high-pressure polymorph of quartz, a common crustal mineral.
HIRAYAMA ASTEROIDS: A asteroids which travel in a cluster along the same orbit.
– i –
ICE: In planetary science, terms refers to water, methane, and ammonia which usually occur as solids in the outer solar system.
IGNEOUS ROCK: When molten rock cools, igneous rock is formed.
IMPACT BASIN: An impact crater that has a rim diameter greater than 185 miles (300 km). There are over 40 impact basins on the Moon. These catastrophic impacts produce faulting and other crust deformations.
IMPACT CRATER: What remains of collisions between an asteroid or meteorite and a planet or moon.
IMPACTITES: A collective term for all rocks being affected by impact as the result of a collision with another planetary body.
IMPACT MELT: Rocks melted during impact. They are extremely uniform in their composition but variable in their texture. They are composed predominantly of the target rocks but may contain a small amount of the impactor.
IMPACT SHOCK: Rocks shocked during impact. Usually seen in quartz minerals.
INCLINATION: the angle between the plane of its orbit and the ecliptic.
IRON METEORITE: An iron meteorite is a meteor made of the metal iron that has fallen to Earth.
– k –
KILOGRAM: (kg) = 1000 grams = 2.2 pounds, the mass of a liter of water.
KILOMETER: kilometer (km) = 1000 meters = 0.62 miles.
KINETIC ENERGY: Kinetic energy is the energy that an object has because of its motion. An object’s kinetic energy is equal to 0.5 times its mass times its velocity squared. In the metric system, kinetic energy is measured in joules or kg-m2/s2.
KIRKWOOD GAPS: relatively empty regions between the main concentrations of asteroids in the Main Asteroid Belt
KUIPER BELT OBJECTS: a disk-shaped region past the orbit of Neptune containing at least 70,000 small icy bodies. It is now considered to be the source of the short-period comets. The Kuiper belt was named after the Dutch-American astronomer Gerard P. Kuiper, who predicted its existence in 1951.
K-T BOUNDARY: The boundary of the Cretaceous-Tertiary eras which marks the end of the age of dinosaurs and the beginning of the age of mammals.
– l –
LIGHT-YEAR: = 9.46053e12 km (= 5,880,000,000,000 miles = 63,239 AU); the distance traveled by light in a year.
LIMB: the outer edge of the apparent disk of a celestial body
LONG PERIOD COMET (LPC): are those comets with a period greater than 200 years.
– m –
MACULA: dark spot.
MAGMA: Molten rock containing dissolved minerals and gasses which crystallize out to form igneous rock.
MANTLE: A zone in a differentiated parent body between the core and the crust.
MAGNITUDE: The degree of brightness of a celestial body designated on a numerical scale, on which the brightest star has magnitude -1.4 and the faintest visible star has magnitude 6, with the scale rule such that a decrease of one unit represents an increase in apparent brightness by a factor of 2.512. Also called apparent magnitude.
MAIN BELT: located between Mars and Jupiter roughly 2 – 4 AU from the Sun; further divided into subgroups: Hungarias, Floras, Phocaea, Koronis, Eos, Themis, Cybeles and Hildas (which are named after the main asteroids in the group).
MARIA: Large impact basins on the Moon filled with basalts.
METEOR: Also “shooting star.” The light from an object, as small as a grain of dust, as it burns through Earth’s atmosphere. Larger rocks, that give off more light, are known as bolides or fireballs.
METEORITE: A rock of extra-terrestrial origin found on Earth
METEOROID: A small rocky object orbiting the Sun; smaller than an asteroid
MINOR PLANETS: A term used for asteroids.
– n –
NEAs: (Near Earth Asteroids) are asteroids which have orbits that bring them within 121 million miles or 195 million kilometers (1.3 A.U.) of the Sun. There are over 250 near-Earth asteroids known and they are classified into three groups: Atens, Apollos, and Amors. NEA’s are the only asteroids that can crash into our planet.
NEAT: (Near-Earth Asteroid Tracking) is a NASA/JPL system that tracks near-earth asteroids using the 1.2-meter- diameter (48-inch) Palomar telescope to track asteroids that come close to the Earth.
NECs: (Near Earth Comets) Short-period comets (period less than 200 years) with orbits that bring them within 121 million miles or 195 million kilometers (1.3 A.U.) of the Sun.
NEOs: (Near Earth Objects) are comets and asteroids that have ventured close to the Earth’s orbit.
– o –
OLD: a planetary surface that has been modified little since its formation typically featuring large numbers of impact craters
OORT CLOUD: the spherical cloud of rock and debris, about six trillion icy objects, surrounding our planetary system which extends approximately 3 light years, approximately 30 trillion, kilometers from the Sun.
OVOID: resembling an egg in shape
– p –
PARSEC: = 206265 AU = 3.26 light year
PEAK RING: Central uplift characterized by a ring of peaks rather than a single peak. Peak rings are typical of larger terrestrial craters above about 50 km in diameter.
PERIHELION: The point in the path of a celestial body that is nearest to the sun.
PERIOD: The time it takes a rock to orbit the sun. For example: long period comets >200 years and short period comets < 200 years.
PERTURB: To cause a planet or satellite to deviate from a theoretically regular orbital motion.
PHAs (Potentially Hazardous Asteroids) MOID=0.05 A.U. (Minimum Orbital Insertion Distance) These rocks may never impact Earth but their closeness is worth a sharp watch. There are over 200 known PHA’s. (link includes daily orbital elements and tables of known PHA’s and further info) See Torino Impact Scale.
PLANAR FEATURES: Microscopic features in grains of quartz or feldspar consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orientations with respect to the grain’s crystal structure.
PLANET: Any large body that orbits a sun. From Greek meaning wanderer.
– r –
RESOLUTION: the amount of small detail visible in an image; low resolution shows only large features, high resolution shows many small details.
RESONANCE: A state in which one orbiting object is subject to periodic gravitational perturbations by another.
– s –
SEMIMAJOR AXIS: the semimajor axis of an ellipse (e.g. a planetary orbit) is 1/2 the length of the major axis which is a segment of a line passing thru the foci of the ellipse with endpoints on the ellipse itself. The semimajor axis of a planetary orbit is also the average distance from the planet to its primary. The periapsis and apoapsis distances can be calculated from the semimajor axis and the eccentricity by rp = a(1-e) and ra = a(1+e).
SHATTER CONE: Striated conical fracture surfaces produced by meteorite impact into fine-grained brittle rocks such as limestone.
SHIELD: Any of several extensive regions where ancient Precambrian crystalline rocks are exposed at the Earth’s surface, for example, the Canadian Precambrian Shield
SHOCKED QUARTZ: Quartz that has undergone deformation due to extreme pressure and heat. It has been found in the layer that marks the K-T boundary.
SHOCK METAMORPHISM: The production of irreversible chemical or physical changes in rocks by a shock wave generated by impact, or detonation of high-explosive or nuclear devices.
SHOEMAKER, Gene: Pioneered the field of impact cratering with his landmark studies of Barringer Crater (a.k.a. Meteor Crater) in Arizona, and as a chief geologist he taught the Apollo astronauts about rocks on the moon. Also a pioneer of theories of impact-induced mass extinctions in the geologic past, and the search for Earth-crossing asteroids and comets. He and his wife Carolyn and David Levy were the team that discovered the famed comet that smacked into Jupiter in 1994.
SHOEMAKER-LEVY 9: SL-9 was a short-period comet that was discovered by Eugene and Carolyn Shoemaker and David H. Levy. As the comet passed close by Jupiter, Jupiter’s gravitational forces broke the comet apart. Fragments of the comet collided with Jupiter for six days during July 1994, causing huge fireballs in Jupiter’s atmosphere that were visible from Earth.
SHORT PERIOD COMETS (SPC): are those comets with a period less than 200 years
SIDEROPHILE ELEMENTS: An element with a weak affinity for oxygen and sulfur such as iridium, osmium, platinum, and palladium, that, in chemically segregated asteroids and planets, are found in the metal-rich interiors. Consequently, these siderophile elements are extremely rare on Earth’s surface.
SI UNITES 1564-1616 SI is an abbreviation for systeme internationale, which has become the worldwide adopted standard for units of measurement.
SILICATE: a compound containing silicon and oxygen (e.g. olivine)
STISHOVITE: A dense, high-pressure phase of quartz that has so far been identified only in shock-metamorphosed quartz-bearing rocks from meteorite impact craters.
SUBLIME: (or sublimate) to change directly from a solid to a gas without becoming liquid
– t –
TARGET ROCKS: The surface rocks that an asteroid or comet impactor smashes into in an impact event.
TORINO IMPACT SCALE: Developed in 1999, a scale which describes the risks of a threat of any NEO.
TROJANS: located near Jupiter’s Lagrange points (60 degrees ahead and behind Jupiter in its orbit). Several hundred such asteroids are now known; it is estimated that there may be a thousand or more. This name derives from a generalization of the names of two of the largest asteroids in Jupiter’s Lagrange points: 624 Hektor and 911 Agamemnon. Saturn’s satellites are also sometimes called Trojans.
TECTONIC: deformation forces acting on a planet’s crust.
TEKTITES: Natural, silica-rich, homogeneous glasses produced by complete melting and dispersed as droplets during terrestrial impact events. They range in color from black or dark brown to gray or green and most are spherical in shape. Tektites have been found in four regional deposits or “strewn fields” on the Earth’s surface: North America, Czechoslovakia (the moldavite tektites), Ivory Coast, and Australasia.
TIDAL HEATING: frictional heating of a satellite’s interior due to flexure caused by the gravitational pull of its parent planet and possibly neighboring satellites.
– v –
VELOCITY: Both the speed and the direction that a body is moving. It has more information than speed alone. Velocity is a vector
VOLATILE: As a noun, this refers to substances that are gasses at ordinary temperatures. In astronomy, it includes hydrogen, helium, water, ammonia, carbon dioxide and methane.
– y –
YOUNG: In describing a planetary surface, “young” means that the visible features are of relatively recent geologic origin. Older features have been eroded or destroyed by lava flows. Young surfaces exhibit few impact craters and are typically varied and complex.
“Today, thanks to the pioneering asteroid survey Spacewatch and similar projects, our planetary system appears as a humming hive populated with countless asteroids circling the sun like a swarm of bees.” — Space Daily
Classifications of Space Rocks
1 AU = 1 Astronomical Unit = 93 million miles = 149 million kilometers
Inclination = degrees from the elliptic plane of the solar system, like that swarm of bees.
Atens
orbit the Sun inside Earth’s orbit, crossing our planet’s orbit no less than once per year.
Mineralogically, meteorites consist of varying amounts of nickel-iron alloys, silicates, sulfides, and several other minor phases. Classification is then made on the basis of the ratio of metal to silicate present in the various compositions. No two meteorites are completely alike, and specific compositional and structural features give a particular meteorite its unique identity.
Irons
Rare, (est. only 5%) characterized by the presence of two nickel-iron alloy metals: kamacite and taenite, combined with minor amounts of non-metallic phases and sulfide minerals, form three basic subdivisions of irons. Depending upon the percentage of nickel to iron, these subdivisions are classified as:
hexahedrites (4-6% Ni)
octahedrites (6-12% Ni)
ataxites (12+% Ni)
Octahedrites, which are the most common type of iron meteorite, exhibit a unique structural feature called the Widmanstatten pattern when etched with a weak acid. This unique crystal pattern is the result of the combination of the two nickel-iron minerals kamacite and taenite being present in approximately equal amounts.
Stony Irons
Achondrite Meteorites –Millbillillie
Consist of almost equal amounts of nickel-iron alloy and silicate minerals. Although all stony-irons may not be genetically related or have similar composition, they are combined into one group and divided into two subgroups for convenient classification. The Pallasite group is characterized by olivine crystals surrounded by a nickel-iron structure which forms a continuous enclosing network around the silicate portion. Mesosiderites, on the other hand, consist mainly of plagioclase and pyroxene silicates in the form of heterogeneous aggregates intermixed with the metal alloy. No distinct separation between the metal and silicate phases is readily apparent as it is with the Pallasites.
Stones 100.3 grams of
Allende Meteorite
carbonaceous
chrondrite
The most abundant of the three meteorite groups and come closest to resembling earth rocks in their appearance and composition. The major portion of these meteorites consists of the silicate minerals olivine, pyroxene, and plagioclase feldspars. Metallic nickel-iron occurs in varying percentages and is accompanied by an iron-sulfide mineral. Aside from
being the most abundant meteorite type, stony meteorites have the greatest variety in composition, color, and structure. One particular structural feature called chondrules divides the group into two main subgroups:
Chrondrites, those with chondrules
Achondrites, those without chondrules
Many scientists believe that these small, rounded, nearly spherical chondrules may represent the most primitive material in the solar system.
"Nowadays, of course, the politically correct
way to group organisms, especially prokaryotes, is on a genetic basis,
i.e., by comparison of the nucleotide sequences of the small subunit ribosomal
RNA that is contained in all cellular organisms."
Notes:
Created 2001, Updated: Feb 2007, last update (code clean) Apr 2017
>20 km The formation of impact craters as small as 20 km could produce light reductions and temperature disruptions similar to a nuclear winter. Such impacts occur on Earth with a frequency of two or three every million years.
The impact of comets has profoundly influenced the story of life." -- Gene Shoemaker
ASTROGEOLOGIST Gene Shoemaker
Gene Shoemaker at his office in Flagstaff, Arizona
Gene Shoemaker's life's work in papers and abstracts is an awesome contribution to the study of astrogeology. Unfortunately, a list doesn't convey the inspiration he passed around among friends and colleagues.
1948
1. Shoemaker, E.M., 1948, Petrology of the Hopewell Series in the Ojo Caliente of New Mexico: California Institute of Technology, unpublished Masters Thesis.
1953
2. Shoemaker, E.M., 1953, Thirty selected papers -- an annotated bibliography of the Colorado Plateau: U.S. Geological Survey, 6 p.
1954
3. Shoemaker, E.M., 1954, Structural features of southeastern Utah and adjacent parts of Colorado, New Mexico, and Arizona: Utah Geological Society, Guidebook to the Geology of Utah, no. 9, p. 48-69.
1955
4. Shoemaker, E.M., 1955, Preliminary geologic map of the Juanita Arch quadrangle, Colorado: U.S. Geological Survey Mineral Investigation Field Studies Map, MF-28.
5. Shoemaker, E.M., 1955, Geology of the Juanita Arch quadrangle, Colorado: U.S. Geological Survey Quadrangle Map GQ 81.
6. Shoemaker, E.M., 1955, Preliminary map of the Rock Creek quadrangle, Colorado: U.S. Geological Survey Mineral Investigation Field Studies Map, MF-23.
1956
7. Shoemaker, E.M., 1956, Geology of the Rock Creek quadrangle, Colorado: U.S. Geological Survey Quadrangle Map GQ 83.
8. Shoemaker, E.M., 1956, Occurrence of uranium in diatremes on the Navajo and Hopi Reservations, Arizona, New Mexico, and Utah: United Nations, Geology of Uranium and Thorium: International Conference on Peaceful Uses of Atomic Energy, Geneva, August 1955, Proceedings, v. 6, p. 412-417. Slightly revised, in Page, L.R., Contributions to the geology of uranium and thorium...: U.S. Geological Survey Professional Paper 300, p. 179-185.
9. Shoemaker, E.M., 1956, Precambrian rocks of the north-central Colorado Plateau: Intermountain Association of Petroleum Geologists Field Conference, 7th, Annual Field Conference, p. 54-59.
10. Shoemaker, E.M., 1956, Structural features of the central Colorado Plateau and their relation to uranium deposits, in Page, L.R., Contributions to the geology of uranium and thorium ...: U.S. Geological Survey Professional Paper 300, p. 155-170.
1958
11. Shoemaker, E.M., Case, J.E., and Elston, D.P. 1958, Salt anticlines of the Paradox Basin: Intermountain Association of Petroleum Geologists, Guidebook, 9th, Annual Field Conference, p. 39-59.
1959
12. Shoemaker, E.M., Miesch, A.T., Newman, W.L., and Riley, L.B., 1959, Elemental composition of the sandstone-type deposits, in Garrels, R.M., and Larsen, E.S., ed., Compilers, Geochemistry and Mineralogy of the Colorado Plateau uranium ores: U.S. Geological Survey Professional Paper 320, p. 25-54.
13. Shoemaker, E.M., and Newman, W.L., 1959, Moenkopi Formation (Triassic? and Triassic) in the salt anticline region, Colorado and Utah: American Association of Petroleum Geologists Bulletin, v. 43, no. 8, p. 1835-1851.
1960
14. Shoemaker, E.M., 1960, Impact mechanics at Meteor Crater Arizona, unpublished Princeton PhD Thesis, 55 pp.
15. Chao, E.C.T., Shoemaker, E.M., and Madsen, B.M. 1960, First natural occurrence of coesite from Meteor Crater, Arizona: Science, v. 132, no. 3421, p. 220-222.
16. Elston, D.P., and Shoemaker, E.M., 1960, Late Paleozoic and early Mesozoic structural history of the Uncompahgre front: Four Corners Geological Society, 3rd Field Conference, Guidebook, p. 47-55.
17. Miesch, A.T., Shoemaker, E.M. Newman, W.L., and Finch, W.I., 1960, Chemical composition as a guide to the size of sandstone-type uranium deposits in the Morrison Formation on the Colorado Plateau: U.S. Geological Survey Bulletin, 1112-B, p. 17-61.
18. Shoemaker, E.M., 1960, Ballistics of the Copernican ray system: Lunar and Planetary Exploration Colloquium, Proceedings, v. 2, no. 2, p. 7-21.
19. Shoemaker, E.M., 1960, Brecciation and mixing of rock by strong shock: Article 192: U.S. Geological Survey Professional Paper 400-B, p. B423-B425.
20. Shoemaker, E.M., 1960, Penetration mechanics of high velocity meteorites, illustrated by Meteor Crater, Arizona: International Geological Congress, 21st, Copenhagen, 1960, Report, pt. 18, p. 418-434.
1961
21. Eggleton, R.E., and Shoemaker, E.M., 1961, Breccia at Sierra Madera, Texas: Article 342: U.S. Geological Survey Professional Paper 424-D, p. D151-D153.
22. Elston, D.P., and Shoemaker, E.M., 1961, Preliminary structure contour map on top of salt in the Paradox Member of the Hermosa Formation in the Salt Anticline region, Colorado and Utah: U.S. Geological Survey Oil and Gas Investigation Map OM 209.
23. Landis, E.R., Shoemaker, E.M., and Elston, D.P., 1961, Early and late growth of the Gypsum Valley salt anticline, San Miguel County, Colorado: U.S. Geological Survey Professional Paper 424-C, p. 131-136.
24. Shoemaker, E.M., 1961, Ballistics and throwout calculations for the lunar crater Copernicus: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., pt. 2: University of California, Livermore, Report UCRL-6438, Paper Q, 31 p. (Report prepared for U.S. Atomic Energy Commission).
25. Shoemaker, E.M., and Chao, E.C.T., 1961, New evidence for the impact origin of the Ries Basin, Bavaria, Germany: Journal of Geophysical Research, v. 66, no. 10, p. 3371-3378.
26. Shoemaker, E.M., and Chao, E.C.T., 1961, New evidence for the impact origin of the Ries Basin, Bavaria, Germany: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., part 1: University of California, Livermore, Report UCRL-6438, Paper B, 13 p. (Report prepared for the U.S. Atomic Energy Commission).
27. Shoemaker, E.M., and Eggleton, R.E., 1961, Terrestrial features of impact origin: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., part 1: University of California, Livermore, Report UCRL-6438, Paper A, 27 p. (Report prepared for the U.S. Atomic Energy Commission).
28. Shoemaker, E.M., Gault, D.E., and Lugn, R.V., 1961, Shatter cones formed by high-speed impact in dolomite: Article 417: U.S. Geological Survey Professional Paper 424-D, p. D365-D368.
29. Moore, H.J., Gault, D.E., Lugn, R.V., and Shoemaker, E.M., 1961, Hypervelocity impact of steel into Coconino sandstone: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., part 2: University of California, Livermore, Report UCRL-6438, Paper N, 23 p. (Report prepared for the U.S. Atomic Energy Commission).
1961
21. Eggleton, R.E., and Shoemaker, E.M., 1961, Breccia at Sierra Madera, Texas: Article 342: U.S. Geological Survey Professional Paper 424-D, p. D151-D153.
22. Elston, D.P., and Shoemaker, E.M., 1961, Preliminary structure contour map on top of salt in the Paradox Member of the Hermosa Formation in the Salt Anticline region, Colorado and Utah: U.S. Geological Survey Oil and Gas Investigation Map OM 209.
23. Landis, E.R., Shoemaker, E.M., and Elston, D.P., 1961, Early and late growth of the Gypsum Valley salt anticline, San Miguel County, Colorado: U.S. Geological Survey Professional Paper 424-C, p. 131-136.
24. Shoemaker, E.M., 1961, Ballistics and throwout calculations for the lunar crater Copernicus: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., pt. 2: University of California, Livermore, Report UCRL-6438, Paper Q, 31 p. (Report prepared for U.S. Atomic Energy Commission).
25. Shoemaker, E.M., and Chao, E.C.T., 1961, New evidence for the impact origin of the Ries Basin, Bavaria, Germany: Journal of Geophysical Research, v. 66, no. 10, p. 3371-3378.
26. Shoemaker, E.M., and Chao, E.C.T., 1961, New evidence for the impact origin of the Ries Basin, Bavaria, Germany: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., part 1: University of California, Livermore, Report UCRL-6438, Paper B, 13 p. (Report prepared for the U.S. Atomic Energy Commission).
27. Shoemaker, E.M., and Eggleton, R.E., 1961, Terrestrial features of impact origin: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., part 1: University of California, Livermore, Report UCRL-6438, Paper A, 27 p. (Report prepared for the U.S. Atomic Energy Commission).
28. Shoemaker, E.M., Gault, D.E., and Lugn, R.V., 1961, Shatter cones formed by high-speed impact in dolomite: Article 417: U.S. Geological Survey Professional Paper 424-D, p. D365-D368.
29. Moore, H.J., Gault, D.E., Lugn, R.V., and Shoemaker, E.M., 1961, Hypervelocity impact of steel into Coconino sandstone: Proceedings of the Geophysical Laboratory/Lawrence Radiation Laboratory Cratering Symposium, Washington, D.C., part 2: University of California, Livermore, Report UCRL-6438, Paper N, 23 p. (Report prepared for the U.S. Atomic Energy Commission).
1962
30. Shoemaker, E.M., 1962, Interpretation of lunar craters, in Kopal, Zdenek, ed., Physics and Astronomy of the Moon: London, Academic Press, p. 283-359.
31. Elston, D.P., Shoemaker, E.M., and Landis, E.R. , 1962, Uncompahgre Front and Salt Anticline Region of Paradox Basin, Colorado and Utah: American Association of Petroleum Geologists Bulletin, v. 46, no. 10, p. 1857-1878.
32. Shoemaker, E.M., Roach, C.H., and Byers, F.M., Jr., 1962, Diatremes and uranium deposits in the Hopi Buttes, Arizona: Petrologic Studies, a volume to honor A. F. Buddington: Geological Society of America, p. 327-355.
33. Shoemaker, E.M., and Hackman, R.J., 1962, Stratigraphic basis for a lunar time scale, in Kopal, Zdenek and Mikhailov, Z.K., eds., The Moon -- Symposium no. 14 of the International Astronomical Union: London, Academic Press, p. 289-300.
34. Shoemaker, E.M., 1962, Exploration of the moon's surface: American Scientist, v. 50, no. 1, p. 99-130.
1963
35. Shoemaker, E.M., 1963, Impact mechanics at Meteor Crater, Arizona, in Middlehurst, B., and Kuiper, G.P., eds., The Moon, Meteorites, and Comets--The Solar System, v. 4: Chicago, University of Chicago Press, p. 301-336.
36. Shoemaker, E.M., Hackman, R.J., and Eggleton, R.E., 1963, Interplanetary correlation of geologic time, in Advances in the Astronautical Sciences, v. 8: New York, Plenum Press, p. 70-89.
37. Shoemaker, E.M., Gault, D.E., Moore, H.J., and Lugn, R.V., 1963, Hypervelocity impact of steel into Coconino sandstone: American Journal of Science, v. 261, no. 7, p. 668-682.
38. Gault, D.E., Shoemaker, E.M., and Moore, H.J., 1963, Spray ejected from the lunar surface by meteoroid impact: National Aeronautics and Space Administration Technical Note D-1767, 39 p.
1964
39. Shoemaker, E.M., 1964, The Moon close up: National Geographic, v. 126, no. 5, p. 690-707.
40. Shoemaker, E.M., 1964, The geology of the Moon: Scientific American, v. 211, no. 6, p. 38-47.
1965
41. Shoemaker, E.M., 1965, Preliminary analysis of the fine structure of the lunar surface in Mare Cognitum, in Ranger VII, part 2, Experimenters' Analyses and Interpretations: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-700, p. 75-134.
42. Shoemaker, E.M., and others, 1965, Report of Geology Working Group, in National Aeronautics and Space Administration 1965 Summer Conference on Lunar Exploration and Science, Falmouth, Massachusetts, July 19-31: National Aeronautics and Space Administration Special Publication SP-88, p. 77-160.
1966
43. Rennilson, J.J., Dragg, J.L., Morris, E.C., Shoemaker, E.M., and Turkevich, E., 1966, Lunar surface topography, in Surveyor I Mission Report, part II: Scientific Data and Results, September 10, 1966: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1023, p. 7-44.
44. Shoemaker, E.M., 1966, When the irresistible force meets the immovable object: Engineering and Science, v. 29, no. 5, p. 11-15.
45. Shoemaker, E.M., 1966, Interpretation of the small craters of the Moon's surface revealed by Ranger VII: Transactions of the International Astronomical Union, General Assembly, Proceedings, 12, Hamburg, Germany, 1964, v. XIIB, p. 662-672.
46. Shoemaker, E.M., 1966, Preliminary analysis of the fine structure of the lunar surface in Mare Cognitum, in Hess, W.N., Menzel, D.H., and O'Keefe, J.A., eds., The Nature of the Lunar Surface: International Astronomical Union-National Aeronautics and Space Administration Symposium, Proceedings, 1965, John Hopkins Press, p. 23-78.
47. Shoemaker, E.M., 1966, Progress in the analysis of the fine structure and geology of the lunar surface from the Ranger VIII and IX photographs, in Ranger VIII and IX, part II: Experimenters' Analyses and Interpretations, March 15, 1966: Jet Propulsion Laboratory, California Institute of Technology, Report No. 32-800, p. 249-336.
48. Shoemaker, E.M., Batson, R.M., and Larson, K.B., 1966, An appreciation of the Luna 9 pictures: Astronautics and Aeronautics, May 1966, p. 40-50.
49. Shoemaker, E.M., with Jaffe, L.D., and others, 1966, Surveyor I: Preliminary results: Science, 152, no. 3730, p. 1737-1750; also published in Surveyor I: A preliminary report: National Aeronautics and Space Administration, Special Publication 126, Washington, D.C.
1967
50. Gault, D.E., Adams, J.B., Collins, R.M., Green, J., Kuiper, G.P., Masursky, Harold, O'Keefe, J.A., Phinney, R.A., and Shoemaker, E.M., 1967, Lunar theory and processes, in Surveyor V Mission Report, Part II: Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1246, p. 177-179; also published in National Aeronautics and Space Administration, Special Publication 163, Washington, D.C., p. 155-156.
51. Gault, D., Collins, R., Gold, T., Green, J., Kuiper, G.P., Masursky, Harold, O'Keefe, J., Phinney, R., and Shoemaker, E.M., 1967, Lunar theory and processes, in Surveyor III Mission Report, Part II. Scientific results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1177, p. 193-213, also published in Surveyor III: A preliminary report: National Aeronautics and Space Administration, Special Publication 146, Washington, D.C., p. 141-156.
52. Schmitt, H.H., Trask, N.J., and Shoemaker, E.M., 1967, Geologic map of the Copernicus quadrangle of the Moon: U.S. Geological Survey Map 1-515 (LAC-58).
53. Shoemaker, E.M., Batson, R.M., Holt, H.E., Morris, E.C., Rennilson, J.J., and Whitaker, E.A., 1967, Television observations from Surveyor III, in Surveyor III Mission Report, Part II, Scientific Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1177, p. 9-67; also published in National Aeronautics and Space Administration, Special Publication 146, p. 9-59.
54. Shoemaker, E.M., Batson, R.M., Holt, H.E., Morris, E.C., Rennilson, J.J., and Whitaker, E.A., 1967, Surveyor V: Television pictures: Science, v. 158, no. 3801, p. 642-652.
55. Shoemaker, E.M., Batson, R.M., Holt, H.E., Morris, E.C., Rennilson, J.J., and Whitaker, E.A., 1967, Television observations from Surveyor V, in Surveyor V Mission Report, Part II: Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1246, p. 7-42; also published in National Aeronautics and Space Administration Special Publication 163, p. 9-42.
1968
56. Gault, D.E., Adams, J.B., Collins, R.J., Kuiper, G.P., Masursky, Harold, O'Keefe, J.A., Phinney, R.A., and Shoemaker, E.M., 1968, Lunar theory and processes, in Surveyor VII Mission Report, Part II: Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1264, p. 267-313; also published in National Aeronautics and Space Administration Special Publication no. 173, p. 233-276.
57. Gault, D.E., Adams, J.B., Collins, R.J., Kuiper, G.P., Masursky, Harold, O'Keefe, J.A., Phinney, R.A., and Shoemaker, E.M., 1968, Lunar theory and processes, in Surveyor Project Final Report, Part II, Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1265, p. 389-405.
58. Gault, D.E., Adams, J.B., Collins, R.J., Kuiper, G.P., Masursky, Harold, O'Keefe, J.A. Phinney, R.A., and Shoemaker, E.M., 1968, Lunar theory and processes: Journal of Geophysical Research, v. 73, no. 12, p. 4115-4131.
59. Jaffe, L.D., Alley, C.O., Batterson, S.A., Christensen, E.M., Dwornik, S.E., Gault, D.E., Lucas, J.W., Muhleman, D.O., Norton, R.H., Scott, R.F., Shoemaker, E.M., Steinbacher, R.H., Sutton, G.H., and Turkevich, A.L., 1968, Principal science results from the Surveyor project, in Surveyor Project Final Report, Part II, Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1265, p. 15-19.
60. Jaffe, L.D., Alley, C.O., Batterson, S.A., Christenson, E.M., Dwornik, S.E., Gault, D.E., Lucas, J.W., Muhleman, D.O., Norton, R.H., Scott, R.F., Shoemaker, E.M., Steinbacher, R.H., Sutton, G.H., and Turkevich, A.L., 1968, Principal science results from Surveyor VII, in Surveyor VII Mission Report, Part II. Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-l264, p. 5-7; also published in National Aeronautics and Space Administration Special Publication 173, p. 1-3.
61. Jaffe, L.D., Batterson, S.A., Brown, W.E., Jr., Christensen, E.M., Gault, D.E., Lucas, J.W., Norton, R.H., Scott, R.F., Shoemaker, E.M., Sutton, G.H., and Turkevich, A.L., 1968, Principal scientific results of the Surveyor 3 mission: Journal of Geophysical Research, v. 73, no. 12, p. 3983-3987.
62. Jaffe, L.D., Batterson, S.A., Brown, W.E. Jr., Christensen, E.M., Dwornik, S.E., Gault, D.E., Lucas, J.W., Norton, R.H., Scott, R.F., Shoemaker, E.M., Sutton, G.H., and Turkevich, A.L., 1968, Principal science results from Surveyor 5: Journal of Geophysical Research, v. 73, no. 22, p. 7165-7167.
63. Morris, E.C., Batson, R.M., Holt, H.E., Rennilson, J.J., Shoemaker, E.M. (Principal Investigator), and Whitaker, E.A., 1968, Television observations from Surveyor VI, in Surveyor VI Mission Report, Part II, Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1262, p. 9-45; also published in National Aeronautics and Space Administration Special Publication 166, p. 11-40.
64. O'Keefe, J.A., Adams, J.B., Gault, D.E., Green, J., Kuiper, G.P., Masursky, Harold, Phinney, R.A., and Shoemaker, E.M., 1968, Theory and processes relating to the lunar maria from the Surveyor experiments, in Surveyor VI Mission Report, Part II: Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1262, p. 171-176; also published in National Aeronautics and Space Administration Special Publication 166, p. 145-149.
65. Shoemaker, E.M., Batson, R.M., Holt, H.E., Morris, E.C., Rennilson, J.J., and Whitaker, E.A., 1968, Television observations from Surveyor III: Journal of Geophysical Research, v. 73, no. 12, p. 3989-4043.
66. Shoemaker, E.M., Batson, R.M., Holt, H.E., Morris, E.C., Rennilson, J.J., and Whitaker, E.A., 1968, Television observations from Surveyor VII, in Surveyor VII Mission Report, Part II, Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1264, p. 9-75; also published in National Aeronautics and Space Administration Special Publication 173, p. 13-81.
67. Shoemaker, E.M., Morris, E.C., Batson, R.M., Holt, H.E., Larson, K.B., Montgomery, D.R., Rennilson, J.J., and Whitaker, E.A., 1968, Television observations from Surveyor, in Surveyor Project Final Report, Part II: Science Results: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1265, p. 21-136; also published in National Aeronautics and Space Administration Special Publication 184, p. 351-367.
1969
68. Gault, D.E. (Chairman), Adams, J.B., Collins, R.J., Gold, T., Kuiper, G.P., Masursky, Harold, O'Keefe, J.A., Phinney, R.A., and Shoemaker, E.M., 1969, Lunar theory and processes, in Surveyor Program Results: National Aeronautics and Space Administration Special Publication 184, p. 351-367.
69. Jaffe, L.D. (Chairman), Alley, C.O., Batterson, S.A., Christensen, E.M., Dwornik, Gault, D.E., Lucas, J.W., Muhleman, D.O., Norton, R.H., Scott, R.F., Shoemaker, E.M., Steinbacher, R.H., Sutton, G.H., and Turkevich, A.L., 1969, Principal scientific results from the Surveyor program, in Surveyor Program Results: National Aeronautics and Space Administration Special Publication 184, p. 13-17.
70. Phinney, R.A., O'Keefe, J.A., Adams, J.B., Gault, D.E., Kuiper, G.P., Masursky, Harold, Collins, R.J., Shoemaker, E.M., 1969, Implications of the Surveyor 7 results: Journal of Geophysical Research, v. 74, no. 25, p. 6053-6080.
71. Shoemaker, E.M., 1969, The lunar regolith, in Randall, C.A. Jr., ed., Extraterrestrial Matter: Conference at Argonne National Laboratory, Proceedings, March 7-8, 1968, Northern Illinois University Press, p. 93-136.
72. Shoemaker, E.M., 1969, Space--Where, now, and why?: Engineering and Science, v. 33, no. l, p. 9-12.
73. Shoemaker, E.M., Bailey, N.G., Batson, R.M., Dahlem, D.H., Foss, T.H., Grolier, M.J., Goddard, E.N., Hait, M.H., Holt, H.E., Larson, K.B., Rennilson, J.J., Schaber, G.G., Schleicher, D.L., Schmitt, H.H., Sutton, R.L., Swann, G.A., Waters, A.C., and West, M.H., 1969, Geologic setting of the lunar samples returned by the Apollo 11 mission, in Apollo 11 Preliminary Science Report: National Aeronautics and Space Administration Special Publication 214, p. 41-83.
74. Shoemaker, E.M., Batson, R.M., Holt, H.E., Morris, E.C., Rennilson, J.J., and Whitaker, E.A., 1969, Observations of the lunar regolith and the Earth from the television camera on Surveyor 7: Journal of Geophysical Research, v. 74, no. 25, p. 6081-6119.
75. Shoemaker, E.M., and other members of the Lunar Sample Preliminary Examination Team, 1969, Preliminary examination of lunar samples from Apollo 11: Science, v. 165, no. 3899, p. 1211-1227.
1970
76. Shoemaker, E.M., Batson, R.M., Bean, A.L., Conrad, C., Dahlem, D.H., Goddard, E.N., Hait, M.H., Larson, K.B., Schaber, G.G., Schleicher, D.L., Sutton, R.L., Swann, G.A., and Waters, A.C., 1970, Preliminary geologic investigation of the Apollo 12 landing site, in Apollo 12, Preliminary Science Report: National Aeronautics and Space Administration Special Publication 235.
77. Shoemaker, E.M., Hait, M.H., Swann, G.A., Schleicher, D.L., Dahlem, D.H., Schaber, G.G., Sutton, R.L., 1970, Lunar regolith at Tranquility Base: Science, v. 167, no. 3918, p. 452-455. ib
78. Shoemaker, E.M., Batson, R.M., Bean, A.L., Conrad, C., Dahlem, D.H., Goddard, E.N., Hait, M.H., Larson, K.B., Schaber, G.G., Schleicher, D.L., Sutton, R.L., Swann, G.A., and Waters, A.C., 1970, Preliminary examination of lunar samples from Apollo 12: Science, v. 167, no. 3923, p. 1325-1339.
79. Shoemaker, E.M., Hait, M.H., Swann, G.A., Schleicher, D.L., Schaber, G.G., Sutton, R.L., Dahlem, D.H., Goddard, E.N., and Waters, A.C., 1970, Origin of the lunar regolith at Tranquility Base: Apollo 11 Lunar Science Conference, Proceedings, v. 3, Supplement 1, p. 2399-2412.
80. Shoemaker, E.M., and Morris, E.C., 1970, Physical characteristics of the lunar regolith determined from Surveyor television observations: Radio Science, v. 5, p. 129-155.
81. Shoemaker, E.M., and Morris, E.C., 1970, Surveyor Final Reports--Geology: Craters: Fragmental Debris; Fragmental Debris Physics: Icarus, v. 12, p. 167-212.
1971
82. Anderson, O.L., Burk, C.A., Cox, A.V., Drake, C.L., Goldsmith, J.R., Knopoff, L., Maxwell, J.C., Press, F., Shoemaker, E.M., van Andel, T., 1971, Geodynamics Project: Development of a U.S. Program: EOS, American Geophysical Union, Transactions, v. 52, no. 5, p. 396-405.
83. Shoemaker, E.M., 1971, Origin of fragmental debris on the lunar surface and the history of bombardment of the Moon: Instituto de Investigaciones Geologicas de la Diputacion Provincial, Universidad de Barcelona, v. 25, p. 27-56.
1972
84. Shoemaker, E.M., 1972, Geology of the Moon and Project Apollo (Published in Japanese): Gendai Sedai Hyakkajiten (World Now Encyclopedia), Ryuzi Mikuni, ed., p. 826-827.
85. Stuart-Alexander, D.E., Shoemaker, E.M., and Moore, H.J., 1972, Geologic map of the Mule Ear diatreme, San Juan County, Utah: U.S. Geological Survey Map I-674.
1974
86. Goetz, A.F.H., Billingsley, F.C., Elston, D.P., Lucchitta, Ivo, and Shoemaker, E.M., 1974, Geologic applications of ERTS images on the Colorado Plateau, Arizona, in Third Earth Resources Technology Satellite - 1 Symposium, v. I, Section A: National Aeronautics and Space Administration, Washington, D.C., p. 719-744.
85. Shoemaker, E.M., and Kieffer, S.W., 1974, Guidebook to the Geology of Meteor Crater: Prepared for the 37th Annual Meeting of the Meteoritical Society, August 4, 1974, 66 p.
1975
87. Goetz, A.F.H., Billingsley, F.C., Gillespie, A.R., Abrams, M.J., Squires, R.L., Shoemaker, E.M., Lucchitta, Ivo, and Elston, D.P., 1975, Application of ERTS images and image processing to regional geologic problems and geologic mapping in Northern Arizona: Jet Propulsion Laboratory, California Institute of Technology, Technical Report No. 32-1597, 188 p.
88. Shoemaker, E.M., and Stephens, H.G., 1975, First photographs of the Canyon Lands: Four Corners Geological Society of Guidebook, Field Conference, 8th, Canyonlands, p. 111-122.
89. Shoemaker, E.M., and Swann, G.A., Conveners, 1975, Continental drilling, report of the workshop on continental drilling: Shoemaker, E.M., ed., Carnegie Institution of Washington, 55 p.
1976
90. Helin, E.F., and Shoemaker, E.M., 1976, 1976 AA: Discovery of a minor planet: Astronomy, v. 4, p. 12-13.
91. Shoemaker, E.M., Helin, E.F., and Gillett, S.L., 1976, Populations of planet-crossing asteroids: Geologica Romana, v. 15, p. 487-489.
1977
92. Helin, E.F., and Shoemaker, E.M., 1977, Discovery of 1976 AA: Icarus, v. 31, p. 415-419.
93. Shoemaker, E.M., 1977, Astronomically observable crater-forming projectiles, in Roddy, D.J., Pepin, R.O., and Merrill, R.B., eds., Impact and explosion cratering: Planetary and terrestrial implications: New York, Pergamon Press, p. 617-628.
94. Shoemaker, E.M., 1977, Why study impact craters?, in Roddy, D.J., Pepin, R.O, and Merrill, R.B., eds., Impact and explosion cratering: Planetary and Terrestrial Implications: New York, Pergamon Press, p. 1-10.
95. Shoemaker, E.M., and Helin, E.F., 1977, Populations of planet-crossing asteroids and the relationship of Apollo objects to main-belt asteroids and comets, in Delsemme, A.H., ed., Comets, Asteroids, Meteorites: Interrelations, Evolution and Origins: University of Toledo, p. 297-300.
1978
96. Shoemaker, E.M., 1978, Search for near-Earth asteroids, in Arnold, J.R., and Duke, M.B., eds., Summer workshop on near-Earth resources: National Aeronautics and Space Administration Conference Publication 2031, p. 57-61.
97. Shoemaker, E.M., and Helin, E.F., 1978, Earth-approaching asteroids: populations, origin, and compositional types, in Morrison, D., and Wells, W.C., eds., Asteroids: An Exploration Assessment: National Aeronautics and Space Administration Conference Publication 2053, p. 161-176.
98. Shoemaker, E.M., and Helin, E.F., 1978, Earth-approaching asteroids as targets for exploration, in Morrison, D., Wells, W.C., eds.: National Aeronautics and Space Administration Conference Publication 2053, p. 245-256.
99. Shoemaker, E.M., Squires, R.L., and Abrams, M.J., 1978, The Bright Angel and Mesa Butte fault system of northern Arizona, in Geology of Northern Arizona: Geological Society of America, Rocky Mountain Society Meeting, Flagstaff, Arizona, p. 355-391.
1979
100. Shoemaker, E.M., and Smith, B.A., 1979, Dynamics of volcanic plumes on Io: Nature, v. 280, p. 743-746.
101. Helin, E.F., and Shoemaker, E.M., 1979, Palomar planet-crossing asteroid survey 1973-1978: Icarus, v. 40 p. 321-328.
102. Shoemaker, E.M., and Kieffer, S.W., 1979, Guidebook to the geology of Meteor Crater, Arizona (revised): Center for Meteorite Studies, Publication, No. 17, Arizona State University, Tempe, Arizona, 66 p.
103. Shoemaker, E.M., Squires, R.L., and Abrams, M.J., 1979, Bright Angel and Mesa Butte fault systems of northern Arizona: Geological Society of America Memoir 152, p. 341-367.
104. Shoemaker, E.M., Williams, J.G., Helin, E.F., and Wolfe, R.F., 1979, Earth-crossing asteroids: Orbital classes, collision rates with Earth and origin, in Gehrels, T., ed., Asteroids: University of Arizona Press, p. 253-282.
105. Smith, B.A., Shoemaker, E.M., Kieffer, S.W., and Cook, A.F. II, 1979, The role of SO2 in volcanism on Io: Nature, v. 280, p. 738-743.
106. Smith, B.A., Soderblom, L.A., Beebe, R., Boyce, J., Briggs, G., Carr, M.H., Collins, S.A., Cook, A.F. II, Danielson, G.E., Davies, M.E., Hunt, G.E., Ingersoll, A., Johnson, T.V., Masursky, Harold, McCauley, J., Morrison, D., Owen, T., Sagan, C., Shoemaker, E.M., Strom, R., Suomi, V.E., and Ververka, J., 1979, The Galilean Satellites and Jupiter: Voyager 2 Imaging Science Results: Science, v. 206, p. 927-950.
107. Smith, B.A., Soderblom, L.A., Johnson, T.V., Ingersoll, A.P., Collins, S.A., Shoemaker, E.M., Hunt, G.E., Masursky, Harold, Carr, M.H., Davies, M.E., Cook, A.F. II, Boyce, J., Danielson, G.E., Owen, T., Sagan, C., Beebe, R.F., Ververka, J., Strom, R. G., McCauley, J. F., Morrison, D., Briggs, G.A., and Suomi, V.E., 1979, The Jupiter system through the eyes of Voyager I: Science, v. 204, p. 951-972.
1980
108. Purucker, M.E., Elston, D.P., and Shoemaker, E.M., 1980, Early acquisition of characteristic magnetization in red beds of the Moenkopi Formation (Triassic), Gray Mountain, Arizona: Journal of Geophysical Research, v. 85, no. B2, p. 997-1012.
1981
109. Cook, A.F. II, and Shoemaker, E.M., Smith, B.A., Danielson, G.E., Johnson, T.V., and Synnott, S.P., 1981, Volcanic origin of the eruptive plumes on Io: Science, v. 211, no. 4489, p. 1419-1922.
110. Emiliani, C. Kraus, E.B., and Shoemaker, E.M., 1981, Sudden death at the end of the Mesozoic: Earth and Planetary Science Letters, v. 55, p. 317-334.
111. Shoemaker, E.M., 1981, The collision of solid bodies, in Beatty, J.K., O'Leary, B., and Chaikin, A., eds., The New Solar System: Sky Publishing Corporation, Cambridge, Massachusetts, p. 33-45.
112. Shoemaker, E.M., 1981, Lunar Geology, in Hanle, P., and Chamberlain, V. del., eds., Space Science Comes of Age: Perspectives in the History of the Space Sciences: National Air and Space Museum, Smithsonian Institution, p. 51-57.
113. Smith, B.A., Soderblom, L.A., Beebe, R., Boyce, J., Briggs, G., Bunker, A., Collins, S.A., Hansen, C.J., Johnson, T.V., Mitchell, J.L., Terrile, R.J., Carr, M., Cook A.F. II, Cuzzi, J., Pollack, J.B., Danielson, G.E., Ingersoll, A., Davies, M.E., Hunt, G.E., Masursky, Harold, Shoemaker, E.M., Morrison, D., Owen, T., Sagan, C., Ververka, J., Strom, R., and Suomi, V. E., 1981, Encounter with Saturn: Voyager 1 Imaging Science Results: Science, v. 212, no. 4491, p. 136-192.
1982
114. Passey, Q.R., and Shoemaker, E.M., 1982, Craters and basins on Ganymede and Callisto: Morphological indicators of crustal evolution, in Morrison, D., ed., The Satellites of Jupiter: University of Arizona Press, p. 379-434.
115. Shoemaker, E.M., Lucchitta, B.K., Plescia, J.B., Squyres, S.W., and Wilhelms, D.E., 1982, Geology of Ganymede, in Morrison, D., ed., The Satellites of Jupiter: University of Arizona Press, p. 435-520.
116. Shoemaker, E.M., and Wolfe, R.F., 1982, Cratering time scales for the Galilean satellites of Jupiter, in Morrison, D., ed., The Satellites of Jupiter: University of Arizona Press, p. 277-339.
117. Smith, B.A., Soderblom, L., Batson, R., Bridges, P., Inge, J., Masursky, Harold, Shoemaker, E., Beebe, R., Boyce, J., Briggs, G., Bunker, A., Collins, S.A., Hansen, C.J., Johnson, T.V., Mitchell, J.L., Terrile, R.J., Cook, A.F. II, Cuzzi, J., Pollack, J.B., Danielson, G.E., Ingersoll, A.P., Davies, M.E., Hunt, G.E., Morrison, D., Owen, T., Sagan, C., Veverka, J., Strom, R., Suomi, V.E., 1982, A new look at the Saturn system: The Voyager 2 images: Science, v. 215, p. 504-537.
118. Wetherill, G.W., and Shoemaker, E.M., 1982, Collision of astronomically observable bodies with the Earth, in Silver, L.T., and Schultz, T.H., eds., Geological Implications of Impacts of Large Asteroids and Comets on the Earth: Geological Society of America Special Paper 190, p. 1-13.
1983
119. Shoemaker, E.M., 1983, Asteroid and comet bombardment of the Earth: Annual Review of Earth and Planetary Sciences, v. 11, p. 461-494.
120. Shoemaker, E.M., 1983, Response on receiving Arthur L. Day Medal: Geological Society of America Bulletin, v. 94, no. 3, p. 426-427.
1984
121. Morrison, D., Johnson, T.V., Shoemaker, E.M., Soderblom, L., Thomas, P., Veverka, J., and Smith, B.A., 1984, Satellites of Saturn: Geological Perspective, in Gehrels, T., and Matthews, M.S., eds., Saturn: University of Arizona Press, p. 609-639.
122. Shoemaker, E.M., 1984, Large body impacts through geologic time, in Holland, H.D., and Trendall, A.F., eds., Patterns of Change in Earth Evolution, Dahlem Konferenzen: Berlin Springer-Verlag, p.15-40.
123. Shoemaker, E.M., 1984, Response on receiving G. K. Gilbert Award: Geological Society of America Bulletin, v. 95, p. 1001-1002. 124. Shoemaker, E.M., 1984, Acceptance of the Barringer Award: Meteoritics, v. 19, p. 180-182.
1985
125. Berger, W.H., Eddy, J.A., and Shoemaker, E.M., 1985, Effects of extra terrestrial phenomena on the evolution of complex life on Earth, in Milne, D., Raup, D., Billingham, J., Niklaus, K., and Padian, K., eds. The Evolution of Complex and Higher Organisms: National Aeronautics and Space Administration SP-478, p. 111-143.
126. Carrier, G.F., Moran, W.J., Decker, R.W., Eardley, D.M., Friend, J.P., Jones, E.M., Katz, J.I., Keeny, S.M., Jr., Leovy, C.B., Longmire, C.L., McElroy, M.B., Press, W., Ruina, J.P., Shoemaker, E.M., Smith, L., Toon, O.B., and Turco, R.P., 1985, The effects on the atmosphere of a major nuclear exchange: Washington, D.C., National Academy Press, 193 p.
127. Shoemaker, E.M., 1985, Presentation of the G. K. Gilbert Award to George W. Wetherill: citation: Geological Society of America Bulletin, v. 96, p. 1207-1208.
128. Shoemaker, C.S., and Shoemaker, E.M., 1985, Recent discoveries of comets with the Palomar 46-cm Schmidt camera: International Comet Quarterly, v. 7, p. 3-7; also in Reports of Planetary Geology and Geophysics Program 1984: National Aeronautics and Space Administration Technical Memorandum 87563, p. 591-593.
129. Strom, R.G., and Shoemaker, E.M., 1985, Chronology of planetary surfaces, in Veverka, Joseph, ed., Planetary Geology in the 1980's: NASA Scientific and Technical Information Branch, Washington, D.C., p. 75-84.
1986
130. Morgan, M.G., Banerjee, S., Brookins, D.G., Cohen, N., Domenico, P.A., Hirschfeld, R.C., James, H.L., Kulp, J.L., Neill, R.H., Shoemaker, E.M., Wiltshire, S., 1986, Scientific basis for risk assessment and management of uranium mill tailings: Washington, D.C., National Academy Press, 246 p.
131. Shoemaker, E.M., 1986, Presentation of the G. K. Gilbert Award to Walter Alvarez: citation: Geological Society of America Bulletin, v. 97, p. 1406-1407.
132. Shoemaker, E.M., and Wolfe, R.F., 1986, Mass extinctions, crater ages, and comet showers, in Smoluchowski, R., Bahcall, J.N., and Matthews, M., eds., The Galaxy and the Solar System: Tucson, University of Arizona Press, p. 338-386.
133. Smith, B.A., Soderblom, L.A., Beebe, R., Bliss, D., Boyce, J.M., Brahic, A., Briggs, G.A., Brown, R.H., Collins, S.A., Cook, A.F., II, Croft, S.K., Cuzzi, J.N., Danielson, G.E., Davies, M.E., Dowling, T.E., Godfrey, D., Hansen, C.J., Harris, C., Hunt, G.E., Ingersoll, A.P., Johnson, T.V., Krauss, R.J., Masursky, H., Morrison, O., Owen, T., Plescia, J.B., Pollack, J.B., Porco, C.C., Rayes, K., Sagan, C., Shoemaker, E.M., Sromovsky, L. A., Stoker, C., Strom, R.G., Suomi, V.E., Synnott, S.P., Terrile, R. J., Thomas, P., Thompson, W. R., and Veverka, J., 1986, Voyager 2 in the Uranian system: Imaging Science Results: Science, v. 233, p. 43-64.
134. Tanaka, K.L., Shoemaker, E.M., Ulrich, G.E., and Wolfe, E.W., 1986, Migration of volcanism in the San Francisco volcanic field, Arizona: Geological Society of America Bulletin, v. 97, no. 2, p. 129-141.
1987
135. Hut, P., Alvarez, W., Elder, W.P., Hanson, T., Kauffman, E.G., Keller, G., Shoemaker, E.M., and Weissman, P.R., 1987, Comet showers as a cause of mass extinctions: Nature, v. 329, p. 118-126.
136. Keller, G., D'Hondt, S.L., Orth, C.J., Gilmore, J.S., Oliver, P.Q., Shoemaker, E.M., and Molina, E., 1987, Late Eocene impact microspherules: stratigraphy, age, and geochemistry: Meteoritics, v. 22, p. 25-60.
137. Schaber, G.G., Shoemaker, E.M., and Kozak, R.C., 1987, The surface age of Venus: Use of the terrestrial cratering record: Solar System Research, v. 21, p. 89-94.
138. Salyards, S.L., and Shoemaker, E.M., 1987, Landslide and debris-flow deposits in the Thumb Member of the Miocene Horse Spring Formation on the east side of Frenchman Mountain, Nevada: A measure of basin-range extension: Geological Society of America Centennial Field Guide--Cordilleran Section, p. 49-51.
139. Shoemaker, E.M., 1987, Meteor Crater, Arizona: Geological Society of America Centennial Field Guide--Rocky Mountain Section, p. 399-404.
140. Shoemaker, E.M., Pillmore, C.L., and Peacock, E.W., 1987, Remanent magnetization of rocks of latest Cretaceous and earliest Tertiary age from drill core at York Canyon, New Mexico: Geological Society of America Special Paper 190, p. 131-150.
141. Stephens, H.G., and Shoemaker, E.M., 1987, In the footsteps of John Wesley Powell: An album of comparative photographs of the Green and Colorado Rivers, 1871-72 and 1968: Boulder, Colorado, Johnson Books, 286 p.
1988
142. Shoemaker, E.M., 1988, A note about the illustrations, in Cooley, John, The Great Unknown: The Journals of the Historic First Expedition Down the Colorado River: Flagstaff, Arizona, Northland Publishing, p. ix-x.
1989
143. Alvarez, Walter, Hansen, Thor, Hut, Piet, Kauffman, E.G., and Shoemaker, E.M., 1989, Uniformitarinism and the response of Earth scientists to the theory of impact crises, in Clube, S.V.M., ed., Catastrophes and Evolution: Astronomical Foundations, Cambridge, England, Cambridge University Press, p. 13-24.
144. Shoemaker, E.M., 1989, Presentation of the G.K. Gilbert Award to Don Edward Wilhelms: Citation: Geological Society of America Bulletin, v. 101, p. 1103-1004.
145. Shoemaker, E.M., Shoemaker, C.S., Wolfe, R.F., Trojan asteroids: Populations, dynamical structure and origin of the L4 and L5 swarms, in Binzel, R.P. and Matthews, M.S., eds. Asteroids II: Tucson, Arizona, University of Arizona Press, p. 487-523.
146. Smith, B.A., Soderblom, L.A., Banfield, D., Barnet, C., Basilevksy, A.T., Beebe, R., Bollinger, K., Boyce, J.M., Brahic, A., Briggs, G.A., Brown, R.H., Chyba, C., Collins, S.A., Colvin, T., Cook II, A.F., Crisp, D., Croft, S.K., Cruikshank, D., Cuzzi, J.N., Danielson, G.E., Davies, M. E., DeJong, E., Dones, L., Godfrey, D., Goguen, J., Grenier, I., Haemmerle, V.R., Hammel, H., Hansen, C.J., Helfenstein, C.P., Howell, C., Hunt, G.E., Ingersoll, A.P., Janes, D.M., Johnson, T.V., Kargel, J., Kirk, R., Kuehn, D.I., Limaye, S., Masursky, Harold, McEwen, A., Morrison, D., Owen, T., Owen, W., Pollack, J.B., Porco, C.C., Rages, K., Rudy, D., Sagan, C., Schwartz, J., Shoemaker, E.M., Showalter, M., Sicardy, B., Simonelli, D., Spencer, J., Sromovsky, L.A., Stoker, C., Strom, R.G., Suomi, V.E., Synott, S.P., Terrile, R.J., Thomas, P., Thompson, W.R., Verbiscer, A., and Veverka, J., 1989, Voyager 2 at Neptune: Imaging Science results: Science, v. 246, p. 1422-1449.
1990
147. Arvidson, R.E., Grimm, R.E., Phillips, R.J., Schaber, G.G., and Shoemaker, E.M., 1990, On the nature and rate of resurfacing of Venus: Geophysical Research Letters, v. 17, p. 1385-1388.
148. Ostro, S.J., and Shoemaker, E.M., 1990, The extraordinary radar echoes from Europa, Ganymede, and Callisto: A Geological Perspective: Icarus, v. 85, p. 335-345.
149. Shoemaker, E.M., and Shoemaker, C.S., 1990, The collision of solid bodies, in Beatty, J.K., and Chaikin, Andrew, eds., The New Solar System: Cambridge, Mass., Sky Publishing Corporation, p. 259-274.
150. Shoemaker, E.M., Wolfe, R.F., and Shoemaker, C.S., 1990, Asteroid and comet flux in the neighborhood of the Earth, in Sharpton, V.L., and Ward, P.D., eds., Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality: Geological Society of America Special Paper 247, p. 155-170.
151. Soderblom, L.A., Kieffer, S.W., Becker, T.L., Brown, R.H., Cook, A.F., II, Hansen, C.J., Johnson, T.V., Kirk, R.L., and Shoemaker, E.M., 1990, Triton's geyser-like plumes: Discovery and basic characterization: Science, v. 250, p. 410-415.
152. Tanaka, K.L., Onstott, T.C., and Shoemaker, E.M., 1990, Magnetostratigraphy of the San Francisco Volcanic Field, Arizona: U.S. Geological Survey Bulletin 1929, 35 p.
1991
153. Nishizumi, K., Kohl, C.P., Shoemaker, E.M., Arnold, J.R., Klein, J., Fink, D., and Middleton, R., 1991, In situ 10Be-26Al exposure ages at Meteor Crater, Arizona: Geochimica et Cosmochimica Acta. v. 55, p. 2699-2703.
154. Shoemaker, E.M., 1991, Barringer Medal Citation for Richard A.F. Grieve: Meteoritics, v. 26, p. 71.
1993
155. Nozette, Stewart, and Shoemaker, E.M., 1993, Back to the Moon, on to an asteroid: the Clementine mission: The Planetary Report, v. 13, p. 10-15.
156. Shoemaker, E.M., 1993, Presentation of the Day Medal to Susan Werner Kieffer (Citation): GSA Today, March 1993, p. 62.
157. Steiner, M.B., Morales, Michael, and Shoemaker, E.M., 1993, Magnetostratigraphic, biostratigraphic, and lithologic correlations in Triassic strata of the western United States: Applications of Paleomagnetism to Sedimentary Geology, SEPM Spec. Pub. No. 49, p. 41-57.
1994
158. Anderson, R.R., Hartung, J.B., Witzke, B.J., Shoemaker, E.M., and Roddy, D.J., 1994, Preliminary results of the U.S. Geological Survey-Iowa Department of Natural Resources Geological Survey Bureau Manson Core Drilling Project, in Dressler, B.O., Grieve, R.A.F., and Sharpton, V.L., eds., Large Meteorite Impacts and Planetary Evolution: Geological Society of America Special Paper 293, p. 237-247.
159. Carusi, A., Gehrels, T., Helin, E.F., Marsden, B.G., Russell, K.S., Shoemaker, C.S., Shoemaker, E.M., and Steel, D.I., 1994, Near-Earth Objects: Present Search Programs, in Gehrels, T., ed., Hazards Due to Comet and Asteroids, The University of Arizona Press, p. 127-147.
160. Grieve, Richard A.F., and Shoemaker, Eugene M., 1994, The Record of Past Impacts on Earth, in Gehrels, T., ed., Hazards Due to Comets and Asteroids, The University of Arizona Press, p. 417-462.
161. Nozette, Stewart, Rustan, P., Pleasance, L.P., Horan, D.M., Regeon, P., Shoemaker, E.M., Spudis, P.D., Acton, C.H., Baker, D.N., Blamont, J.E., Buratti, B.J., Corson, M.P., Davies, M.E., Duxbury, T.C., Eliason, E.M., Jakosky, B.M., Kordas, J.F., Lewis, I.T., Lichtenberg, C.L., Lucey, P.G., Malaret, E., Massie, M.A., Resnick, J.H., Rollins, C.J., Park, H.S., McEwen, A.S., Priest, R.E., Pieters, C.M., Reisse, R.A., Robinson, M.S., Smith, D.E., Sorenson, T.C., Vorder Breugge, R.W., and Zuber, M.T., 1994, The Clementine Mission to the Moon, Science, December 16, 1994, v. 266, p. 1835-1839.
162. Nozette, Stewart, and Shoemaker, Eugene M., 1994, Clementine Goes Exploring: Sky & Telescope, April 1994, p. 38-39.
163. Plescia, J.B., Shoemaker, E.M., and Shoemaker, C.S., 1994, Gravity survey of the Mount Toondina impact structure, South Australia: Journal of Geophysical Research, v. 99, p. 13,167-13,179.
164. Rabinowitz, David, Bowell, Edward, Shoemaker, Eugene, and Muinonen, Karri, 1994, The Population of Earth-Crossing Asteroids, in Gehrels, T., ed., Hazards Due to Comets and Asteroids, The University of Arizona Press, p. 285-312.
165. Shoemaker, E.M., Robinson, M.S., and Eliason, E.M., 1994, The South Pole Region of the Moon as Seen by Clementine, Science, December 16, 1994, v. 266, p. 1851-1854.
166. Shoemaker, Eugene, Shoemaker, Carolyn, and Levy, David, 1994, Discovering Comet Shoemaker-Levy 9, in Once in a Thousand Lifetimes: A guide to the collision of Comet Shoemaker-Levy 9 with Jupiter, Pasadena, California, The Planetary Society, p. 2-3.
167. Shoemaker, Eugene M., Weissman, Paul R., and Shoemaker, Carolyn S., 1994, The Flux of Periodic Comets Near Earth, in Gehrels, T., ed., Hazards Due to Comets and Asteroids, The University of Arizona Press, p. 313-335.
168. Steiner, M.B., Lucas, S.G., and Shoemaker, E.M., 1994, Correlation and Age of the Upper Jurassic Morrison Formation From Magnetostratigraphic Analysis, in Mario V. Caputo, James A. Peterson and Karen J. Franczyk, eds., Mesozoic Systems of the Rocky Mountain Region, USA, Denver, Colorado, Society for Sedimentary Geology, Rocky Mountain Section, p. 315-330.
170. Bevan, A.W.R., Shoemaker, E.M., and Shoemaker, C.S., 1995, Metallography and thermo-mechanical treatment of the Veevers (IIAB) crater-forming iron meteorite, Records of the Western Australian Museum, v. 17, p. 51-59.
171. Huntoon, P.W. and Shoemaker, E.M., 1995, Roberts Rift, Canyonlands, Utah, A natural hydraulic fracture caused by comet or asteroid impact: Ground Water, v. 33, p. 561-569.
172. Levy, D.H., Shoemaker, E.M., and Shoemaker, C.S., 1995, Comet Shoemaker-Levy 9 Meets Juipter: Scientific American, v. 273, p. 69-75.
173. Shoemaker, E.M., 1995, Comet Shoemaker-Levy 9 at Jupiter: Geophysical Research Letters, v. 22, no. 12, p. 1555-1556.
174. Shoemaker, Gene and Carolyn, 1995, Foreword for The Great Comet Crash: The impact of Comet Shoemaker-Levy 9 on Jupiter, eds. John R. Spencer and Jacqueline Mitton, Cambridge University Press, p. vii-ix.
175. Shoemaker, C.S., and Shoemaker, E.M., 1995, A Comet Like No Other, in The Great Comet Crash: The impact of Comet Shoemaker-Levy 9 on Jupiter, eds. John R. Spencer and Jacqueline Mitton, Cambridge University Press, p. 7-12.
176. Shoemaker, E.M., Hassig, P.J., and Roddy, D.J., 1995, Numerical simulations of the Shoemaker-Levy 9 impact plumes and clouds: A progress report: Geophysical Research Letters, v. 22, p. 1825-1828.
177. Shoemaker, E.M., Boyarchuk, A.A., Canavan, G., Coradini, M., Darrah, J., Harris, A.J., Morrison, D., Mumma, M.J., Rabinowitz, D.L., Rikhova, R., Chapman, C.R., Marsden, B.G., Ostro, S.J., Worden, S.P., Yeomans, D.K., 1995, Report of the Near-Earth Object Survey Working Group, NASA Solar System Exploration Division, 57 p.
178. Stern, S.A., Slater, D.C., Gibson, W., Reitsema, H.J., Delamere, A., Jennings, D.E., Reuter, D.C., Clarke, J.T., Porco, C.C., Shoemaker, E.M., and Spencer, J.R., 1995, The Highly Integrated Pluto Payload System (HIPPS): A Sciencecraft Instrument for the Pluto Mission: EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy VI, SPIE-The International Society for Optical Engineering Proceedings, July 12-14, 1995, San Diego, California, v. 2518, p. 39-58.
180. Brandt, J.C., A'Hearn, M.F., Randall, C.E., Schleicher, D.G., Shoemaker, E.M., and Stewart, A.I.F., 1996, Small comets (SCs) (Rettig, T.W. and Hahn, J.M., eds.): An unstudied population in the solar system inventory: Completing the Inventory of the Solar System ASP Conference Series, v. 107, p. 289-297.
181. Nozette, S., Lichtenberg, C.L., Spudis, P. Bonner, R., Ort, W., Marlaret, E., Robinson, M., and Shoemaker, E.M., 1996, The Clementine Bistatic Radar Experiment: Science, v. 274, p. 1495-1498.
182. Shoemaker, E.M., 1996, Citation of David J. Stevenson for the Whipple Award: EOS, v. 7, p. 84-85.
183. Shoemaker, E.M., 1996, Citation of Baerbel Koesters Lucchitta for the G.K. Gilbert Award: GSA Today, v. 6, no. 3, p. 30-31.
184. Shoemaker, Eugene M. and Shoemaker, Carolyn S., 1996, The Proterozoic impact record of Australia: AGSO Journal of Australian Geology and Geophysics, v. 16, no. 4, p. 379-398.
185. Steiner, M.B., and Shoemaker, E.M., 1996, A hypothesized Manson impact tsunami: Paleomagnetic and stratigraphic evidence in the Crow Creek Member, Pierre Shale: Geological Society of America Special Paper 302, 1996, p. 419-432.
1997
186. Levison, H.F., Shoemaker, E.M., and Shoemaker, C.S., 1997, Dynamical evolution of Jupiter's Trojan asteroids: Nature, v. 385, p. 42-44.
187. McEwen, A.S., Moore, J.M.,and Shoemaker, E.M., 1997, The Phanerozoic impact cratering rate: Evidence from the farside of the Moon: Journal of Geophysical Research, v. 102, p. 9231-9242. 188. Shoemaker, E.M., 1997, Response on receiving the Bowie Medal: EOS, v. 78, p. 53.
189. Shoemaker, E.M., 1997. Response on receiving the American Association of Petroleum Geologists Special Award: Bulletin of America, Association of Petroleum Geologists, v. 81, p. 849.
190. Wynn, J.C. and Shoemaker, E.M., 1997. Secrets of the Wabar Craters: Sky and Telescope, v. 94, no. 5, p. 44-48.
191. Kriens, B.J., K.E. Herkenhoff and Shoemaker, E.M. , 1997. Structure and Kinematics of a Complex Impact Crater, Upheavel dome, Southeast Utah: Brigham Young University Geologic Studies 42, Part II, GSA Guidebook, 1997, p. 19.
1998
192. Wynn, J.C. and Shoemaker, E.M., 1998, The Day the Sands Caught Fire: Scientific American, Nov. 1998, p. 65-71.
193. Shoemaker, E.M., 1998, Impact cratering through geologic time: J. Roy. Astron. Soc. Canada, Ruth Northcott Lecture, v. 92, p. 297-309.
194. Farley, K.A., Montanari, A., Shoemaker, E.M. and Shoemaker, C.S., 1998, Geochemical evidence for a comet shower in the Late Eocene: Science, May 22, 1998, v. 280, p. 1250-1253.
195. Shoemaker, E.M., 1998, Long-term variations in the impact cratering rate on Earth in Grady, M.M., Hutchison, R., McCall, G.J.H., and Rothery, D.A., eds., Meteorites: Flux with Time and Impact Effects, Geol. Soc. London Spec. Pub. No. 140, p. 6-10.
1999
196. Shoemaker, E.M. and Shoemaker, C.S., 1999, The role of collisions: in Beatty, J.K., Petersen, C.C., and Chaikin, Andrew, eds., The New Solar System: Cambridge, MA, Sky Publishing Corp., p.69-85.
197. Shoemaker, E.M. and Uhlherr, H.R., 1999, Stratigraphic relations of australites in the Port Campbell Embayment, Victoria: Meteoritics and Planet. Sci., v. 34, p. 369-384.
198. Kriens, B.J., Shoemaker, E.M., and Herkenhoff, K.E., 1999, Geology of the Upheaval Dome Impact Structure, Southeast Utah: Jour. Geophys. Res. , v.104, p. 18,867-18,887.
Gene Shoemaker’s life’s work in papers and abstracts is an awesome contribution to the study of astrogeology. Unfortunately, a list doesn’t convey the inspiration he passed around among friends and colleagues.
1. Shoemaker, E.M., 1951, Internal structure of the Sinbad
Valley-Fisher Valley salt anticline, Colorado and Utah (abs.): Geological
Society of America Bulletin, v. 62, no. 12, pt. 2, p. 1478.
2. Shoemaker, E.M., 1953, Collapse origin of the diatremes of the
Navajo-Hopi reservations (abs.): Geological Society of America Bulletin,
v. 64, no. 12, pt. 2, p. 1514.
3. Shoemaker, E.M., and Newman, W.L., 1953, Ute Mountains, a laccolithic
feature in southwestern Colorado (abs.): Geological Society of America
Bulletin, v. 64, no. 12, pt. 2, p. 1555.
4. Shoemaker, E.M., 1956, Unusual folds in Moenkopi Formation around
Fisher Valley, Utah (abs.): Geological Society of America Bulletin, v. 67,
no. 12, pt. 2, p. 18.
5. Shoemaker, E.M., Newman, W.L., and Miesch, A.T., 1956, Sources of the
elements in the sandstone-type uranium deposits of the Colorado Plateau
(abs.): International Geological Congress, 20th, Mexico City, 1956,
Resumenes de los trabajos presentados, p. 102-103.
6. Shoemaker, E.M., 1957, Primary structures of maar rims and their
bearing on the origin of Kilbourne Hole and Zuni Salt Lake, New Mexico
(abs.): Geological Society of America Bulletin, v. 68, no. 12, pt. 2, p.
1846.
7. Miesch, A.T., Shoemaker, E.M., Newman, W.L., and Finch, W.I., 1958,
Chemical composition as a guide to the size of sandstone-type uranium
deposits in the Morrison Formation on the Colorado Plateau (abs.):
Economic Geology, v. 53, no. 7, p. 923-924.
8. Miesch, A.T., Shoemaker, E.M., Newman, W.L., and Finch, W.I., 1958,
Chemical composition as a guide to the size of sandstone-type uranium
deposits in the Morrison Formation on the Colorado Plateau (abs.):
Geological Society of America Bulletin, v. 69, no. 12, pt. 2, p. 1613.
9. Shoemaker, E.M., 1959, Structure and Quaternary stratigraphy of Meteor
Crater, Arizona, in the light of shock-wave mechanics (abs.): Geological
Society of America Bulletin, v. 70, no. 12, pt. 2, p. 1748.
10. Shoemaker, E.M., and Chao, E.C.T., 1960, Origin of the Ries Basin,
Bavaria, Germany (abs.): Geological Society of America Bulletin, v. 71,
no. 12, pt. 2, p. 2111-2112.
11. Shoemaker, E.M., and Hackman, R.J., 1960, Stratigraphic basis for a
lunar time scale (abs.): Geological Society of America Bulletin, v. 71,
no. 12, pt. 2, p. 2112.
12. Shoemaker, E.M., 1961, Interplanetary correlation of geologic time
(abs.): American Association of Petroleum Geologists Bulletin, v. 45, no.
1, p. 130.
13. Eggleton, R.E., and Shoemaker, E.M., 1962, Breccia at Sierra Madera,
Texas (abs), in Abstracts for 1961: Geological Society of America Special
Paper 68, p. 169-170.
14. Chao, E.C.T., Shoemaker, E.M., and Madsen, B.M., 1962, First natural
occurrence of coesite from Meteor Crater, Arizona (abs.), in Abstracts for
1961: Geological Society of America Special Paper no. 68, p. 225.
15. Shoemaker, E.M., 1962, Sampling the moon through Kordylewski’s clouds:
Journal of Geophysical Research, v. 67, no. 4, p. 1656-1657.
16. Gault, D.E., Shoemaker, E.M., and Moore, H.J., 1962, The flux and
distribution of fragments ejected from the lunar surface by meteoroid
impact (abs.): EOS, American Geophysical Union, Transactions, v. 43, no.
4, p. 465.
17. Shoemaker, E.M., and Elston, D.P., 1963, Structure and history of the
salt anticlines of the Paradox Basin, Colorado and Utah (abs.) in
Abstracts for 1962: Geological Society of America Special Paper 73, p.
283-284.
18. Shoemaker, E.M., 1963, Astrogeology, a new horizon (abs.), in
Abstracts for 1962: Geological Society of America Special Paper 72, p.
241.
19. Shoemaker, E.M., 1966, Structure of the Jangle U and Teapot Ess
nuclear explosion craters (abs.), in Conference on Shock Metamorphism of
Natural Materials, April 14-16, 1966, Goddard Space Flight Center,
Greenbelt, Maryland, p. 22.
20. Shoemaker, E.M., and Lowery, C.J., 1966, Airwaves associated with
large fireballs and the frequency distribution of energy of large
meteoroids: Meteoritics, Nov. 1966, v. 3, no. 2.
21. Shoemaker, E.M., and Stephens, H.G., 1969, The Green and Colorado
River Canyons observed from the footsteps of Beaman and Hillers 97 years
after Powell (abs.): Geological Society of America, Annual Meeting, 22nd,
Rocky Mountain Section, Abstracts with Programs, 1969, pt. 5, p. 73.
22. Shoemaker, E.M., Lucchitta, Ivo, and Foley, M.G., 1971, Collapse of
the Basin and Range Province and the Colorado River problem (abs.), in 2nd
ARETS Symposium, Proceedings, University of Arizona, p. 196-198.
23. Shoemaker, E.M., 1971, Why explore the geology of Mars (abs.):
Geological Society of America, Abstracts with Programs, v. 3, p. 703.
24. Shoemaker, E.M., Jackson, E.D., and Hait, M.H., 1971, Surficial and
bedrock stratigraphy of the Apollo 12 landing site (abs.): Geological
Society of America, Abstracts with Programs, v. 3, p. 703.
25. Shoemaker, E.M., 1972, Cratering history and early evolution of the
Moon (ext. abs.), in Watkins, C., ed., Revised Abstract of Papers: Lunar
Science Conference, 3rd, p. 696-698.
26. Helsley, C.E., and Shoemaker, E.M., 1973, Magnetostratigraphy of the
Moenkopi Formation (abs.): Geological Society of America, Abstracts with
Programs, v. 5, no. 7, p. 665-666.
27. Purucker, M.E., and Shoemaker, E.M., 1973, Remarkable episode of
instability of the geomagnetic field in Triassic time (abs.):
International Association of Geomagnetism and Aeronomy Bulletin, v. 34, p.
310-311.
28. Shoemaker, E.M., Elston, D.P., and Helsley, C.E., 1973, Depositional
history of the Moenkopi Formation in light of its magnetostratigraphy
(abs): Geological Society of America, Abstracts with Programs, v. 5, no.
7, p. 807-808.
29. Shoemaker, E.M., Squires, R.L., and Abrams, M.J., 1973, The Bright
Angel and Mesa Butte fault systems of northern Arizona (abs.), in Annual
Conference on Remote Sensing in Arid Lands, 4th Proceedings, University of
Arizona, p. 158-159.
30. Shoemaker, E.M., and Purucker, M.E., 1974, “Gray Mountain”
magnetozone in the Moenkopi Formation of Arizona and Utah (abs.): EOS,
American Geophysical Union, Transactions, v. 56, no. 12, p. 1108-1109.
31. Shoemaker, E.M., 1975, Late Cenozoic faulting and uplift of the
Colorado Plateau (abs.): Geological Society of America, Abstracts with
Programs, v. 7, p. 1270.
32. Shoemaker, E.M., and Helin, E.F., 1976, An Empirical test of Opik’s
equation for probabilities of collision of small bodies with the planets
(abs.): American Astronomical Society Bulletin, v. 8, p. 433.
33. Shoemaker, E.M. and Helin, E.F., 1976, Systematic search for
planet-crossing asteroids and the estimation of impact rates on the
terrestrial planets (ext. abs.), in Reports of Accomplishments of
Planetology Programs, 1975-1976: National Aeronautics and Space
Administration Technical Memorandum X-3364, p. 18-22.
34. Champion, D.E., and Shoemaker, E.M., 1977, Paleomagnetic evidence for
episodic volcanism on the Snake River Plain (ext. abs.), in Greeley, R.,
and Black, David, eds., Abstracts for the Planetary Geology Field
Conference on the Snake River Plain, Idaho: National Aeronautics and Space
Administration Technical Memorandum TM-78436, p. 7-9.
35. Helin, E.F., and Shoemaker, E.M., 1977, 1976 UA: Second Asteroid with
Orbit Smaller than Earth’s (abs.): American Astronomical Society Bulletin,
v. 9, p. 461.
36. Kellogg, J.N., and Shoemaker, E.M., 1977, Age determination of
volcanic rocks by spatial frequency of lightning strikes in the San
Francisco volcanic field, Arizona (abs.): EOS, American Geophysical Union,
Transaction, v. 58, p. 376.
37. Shoemaker, E.M., and Helin, E.F., 1977, Present impact cratering rates
on the terrestrial planets and the Moon (ext. abs.), in Reports of
Planetary Geology Program, 1976-1977: National Aeronautics and Space
Administration Technical Memorandum X-3511, p. 74-77.
38. Steiner, M.B., Shive, P.N., and Shoemaker, E.M., 1977, Polarity of the
magnetic field during the Upper and Middle Jurassic (abs.): EOS, American
Geophysical Union, Transactions, v. 58, p. 376.
39. Champion, D.E., Gromme, C.S., and Shoemaker, E.M., 1978, Holocene
geomagnetic secular variation recorded in basaltic lavas of the western
United States (abs.): EOS, American Geophysical Union, Transactions, v.
59, p. 1060.
40. Helin, E.F., Shoemaker, E.M., and Wolfe, R.F., 1978, Ra-Shalom: Third
Member of the Aten class of earth-crossing asteroids (abs.): American
Astronomical Society Bulletin, v. 10, p. 732.
41. Shoemaker, E.M., 1978, Search for near-Earth asteroids (abs.), in
Arnold, J.R., and Duke, M.B., eds., Summer workshop on near-Earth
resources: National Aeronautics and Space Administration Conference
Publication 2031, p. 57-61.
42. Shoemaker, E.M., and Helin, E.F., 1978, Near-Earth asteroids as
targets for exploration (ext. abs.), in Reports of Planetary Geology
Program, 1977-1978: National Aeronautics and Space Administration
Technical Memorandum 79729, p. 20-21.
43. Shoemaker, E.M., Squires, R.L., and Abrams, M.J., 1978, The Bright
Angel and Mesa Butte fault system of northern Arizona, in Geology of
Northern Arizona: Geological Society of America, Rocky Mountain Society
Meeting, Flagstaff, Arizona, p. 355-391.
44. Shoemaker, E.M., 1979, Geology and history of Ganymede and Callisto
(abs.): American Astronomical Society Bulletin, v. 11, p. 585.
45. Shoemaker, E.M., 1979, Geology of Ganymede (ext. abs.): National
Aeronautics and Space Administration Technical Memorandum TM-80339, p.
373-374.
46. Shoemaker, E.M., and Passey, Q.R., 1979, Tectonic history of Ganymede
(abs.): EOS, American Geophysical Union, Transactions, v. 60, p. 869.
47. Shoemaker, E.M., Williams, J.G., Helin, E.F., and Wolfe, R.F., 1979,
Earth-crossing asteroids: Orbital classes, population, and fluctuation of
population in late geologic time (ext. abs.): National Aeronautics and
Space Administration Technical Memorandum TM-80339, p. 3-5.
48. Passey, Q.R., and Shoemaker, E.M., 1980, Global distribution of
craters and multiring structures on Callisto (abs.): American Astronomical
Society Bulletin, v. 12, p. 712.
49. Passey, Q.R., Shoemaker, E.M., and McCauley, J.F., 1980, Craters and
basins on Ganymede and Callisto (abs.): International Astronomical Union
Colloquium No. 57, Session 6, Paper 8.
50. Plescia, J.B., Boyce, J.M., and Shoemaker, E.M., 1980, Ganymede
cratering I: The dark terrain (abs.): American Astronomical Society
Bulletin, v. 12, p. 710.
51. Plescia, J.B., Boyce, J.M., and Shoemaker, E.M., 1980, Ganymede
cratering II: The smooth and grooved terrains (abs.): American
Astronomical Society Bulletin, v. 12, p. 711.
52. Plescia, J.B., Shoemaker, E.M., and Boyce J.M., 1980, The cratering of
Ganymede I: The dark terrain (ext. abs.), in Reports of Planetary Geology
Program-1980: National Aeronautics and Space Administration Technical
Memorandum 82382, p. 55-59.
53. Plescia, J.B., Shoemaker, E.M., and Boyce, J.M., 1980, The cratering
of Ganymede II: Grooved terrain, smooth and Gilgamesh (ext. abs.), in
Reports of Planetary Geology Program-1980: National Aeronautics and Space
Administration Technical Memorandum 82385, p. 60-63.
54. Shoemaker, E.M., 1980, Geologic history of Ganymede (abs.), in
International Astronomical Union Colloquium No. 57, Session 6, Paper 1.
55. Shoemaker, E.M., Bus. S.J., Williams, J.G., and Helin, E.F., 1980,
Search for planet-crossing asteroids with the Palomar 122-cm Schmidt
camera (abs.), in Reports of Planetary Geology Program, 1979-80: National
Aeronautics and Space Administration Technical Memorandum 81776, p. 8-10.
56. Shoemaker, E.M., Helin, E.F., Bus. S.J., and Passey, Q.R., 1980, New
planet-crossing asteroids, 1979, (ext. abs.), in Reports of Planetary
Geology Program-1980: National Aeronautics and Space Administration
Technical Memorandum 82385, p. 3-5.
57. Shoemaker, E.M., and Wolfe, R.F., 1980, Comets and the Galilean
satellites (abs.): American Astronomical Society, Bulletin, v. 12, p. 712.
58. Wenrich-Verbeek, K.J., and Shoemaker, E.M., 1980, Uranium
mineralization in Hopi Buttes, Arizona (abs.): American Association of
Petroleum Geologists, Book of Abstracts, 1980, American Association of
Petroleum Geologists Annual Convention, p. 136-137.
59. Degewij, J., Shoemaker, E.M., Wolfe, R.F., 1981, Low activity comets
in 1981-1982 (abs.): American Astronomical Society Bulletin, v. 13, p.
705.
60. Passey, Q.R., and Shoemaker, E.M., 1981, Age of Callisto’s surface,
regional variation of crater density and model ages of Callisto’s crust
(ext. abs.), in Lunar and Planetary Science XII, Lunar and Planetary
Science Conference, March 16-20, 1981, p. 816-818.
61. Passey, Q.R., Shoemaker, E.M., 1981, Ganymedian thermal gradients from
studies of crater relaxation (abs.): EOS, American Geophysical Union,
Transactions, v. 62, p. 317.
62. Shoemaker, E.M., 1981, Collision of asteroids and comets with planets
and satellites in late geologic time (abs.), in Papers presented to the
Conference on Large Body Impacts and Terrestrial Evolution: Geological,
Climatological, and Biological Implications, Lunar and Planetary
Institute: National Academy of Sciences, Contribution No. 449, p. 8.
63. Shoemaker, E.M., 1981, Crustal evolution of Callisto and Ganymede
(abs.): EOS, American Geophysical Union, Transactions, v. 62, p. 3l7.
64. Shoemaker, E.M., 1981, The icy satellites of Saturn (abs.): EOS,
American Geophysical Union, Transactions, v. 62, p. 254.
65. Shoemaker, E.M., 1981, Impact record of the planets and satellites
(abs.): Geological Society of America Annual Meeting, Abstracts with
Programs, v. 13, p. 553.
66. Shoemaker, E.M., Shoemaker, C.S., Helin, E.F., Bus, S.J., and Wolfe,
R.F., 1981, Survey for bright Mars-crossing asteroids (ext. abs): National
Aeronautics and Space Administration Technical Memorandum 84211,
Representatives of Planetary Geology Program, 1981, p. 17-19.
67. Shoemaker, E.M., and Wolfe, R.F., 1981, Evolution of the Saturnian
satellites: The role of impact (ext. abs.), in Satellites of Saturn, Lunar
and Planetary Science XII, Supplement A, p. 1-3.
68. Bus, S.J., Helin, E.F., Dunbar, R.S., and Shoemaker, E.M., Dawe, J.,
Barrow, J., Hartley, M., Morgan, D., Russell, K., and Savage, A., 1982,
The United Kingdom – Caltech Asteroid Survey (ext. abs.), in Reports of
Planetary Geology Program-1982: National Aeronautics and Space
Administration Technical Memorandum 85127, p. 53-56.
69. Cook, A.F., Shoemaker, E.M., Soderblom, L.A., Mullins, K.F., and
Fiedler, R., 1982, Volcanism in ice on Europa (abs.), in Reports of
Planetary Geology Program-1982: National Aeronautics and Space
Administration Technical Memorandum 85127, p. 415-416.
70. Gehrels, T., McMillan, R., Frecker, J., Roland, E., Stoll, C., Doose,
L., Shoemaker, E., Nozette, S., Boesgaard, H., 1982, Progress report on
the Spacewatch camera (abs.): American Astronomical Society Bulletin, v.
14, p. 728.
71. Passey, Q.R., and Shoemaker, E.M., 1982, Early thermal histories of
Ganymede and Callisto (extended abs.): Lunar and Planetary Science XIII,
p. 619-620.
72. Shoemaker, E.M., 1982, Bombardment of the Earth from late stages of
accretion to modern times, (abs.): Geological Society of America,
Abstracts with Programs 1982, New Orleans, Louisiana, v. 14, p. 616.
73. Andrews, R.S., and Shoemaker, E.M., 1983, Continental Scientific
Drilling Program: An opportunity for coordinated research (abs.):
Geological Society of America, Abstracts with Programs, 1983, Rocky
Mountain Section, p. 434.
74. Shoemaker, E.M., 1983, Impacts and extinctions; a planetary
perspective on evolutionary biology (abs.), in (Herschman, Arthur, ed.),
National Meeting of the American Association of Science, Abstract Papers,
149th: AAAS Publication, 8302, p. 13-14.
75. Shoemaker, E.M., and Herkenhoff, K.E., 1983, Impact origin of Upheaval
Dome, Utah (abs.): EOS, American Geophysical Union, Transactions, v. 64,
p. 747; also in Reports of Planetary Geology Program-1983: National
Aeronautics and Space Administration Technical Memorandum 86246, p. 93.
76. Shoemaker, E.M., Pillmore, C.L., Tshudy, R.H., and Orth, C.J., 1983,
Characteristic magnetization of Cretaceous/Tertiary boundary claystone in
Raton Basin is reversed (abs.): Geological Society of America, Abstracts
with Program, 1983, Rocky Mountain Section, p. 309.
77. Wolfe, R.F., Degewij, J., Shoemaker, E.M., 1983, The perihelion
brightness surge of short-period comets (abs.): American Astronomical
Society Bulletin, v. 15, p. 807; also in Reports of Planetary Geology
Program-1983: National Aeronautics and Space Administration Technical
Memorandum 86246, p. 62.
78. Shoemaker, E.M., Bus, S.J., Dunbar, R.S., Helin, E.F., Dawe, J.,
Barrow, J., Hartley, M., Morgan, D., Russell, K., and Savage, A., 1984,
Mars-crossing asteroids discovered in the UK-Caltech Asteroid Survey
(abs.): American Astronomical Society Bulletin, v. 16, p. 691.
79. Shoemaker, E.M., and Herkenhoff, K.E., 1984, Upheaval Dome impact
structure (abs.), in Lunar and Planetary Science XV, p. 778-779.
80. Shoemaker, E.M. and Shoemaker, C.S., 1984, Survey for Mars-crossing
asteroids, 1983 (abs.), in Reports of Planetary Geology Program-1983:
National Aeronautics and Space Administration Technical Memorandum 86246,
p. 50.
81. Shoemaker, E.M., Steiner, M.B., Fassett, J.E., and Tschudy, R. H.,
1984, Magnetostratigraphy of Upper Cretaceous rocks at Mesa Portales, New
Mexico (abs.): Geological Society of America, Abstracts with Programs,
Rocky Mountain Section, p 255.
82. Shoemaker, E.M.,and Wolfe, R.F., 1984, Evolution of the Uranus-Neptune
Planetesimal Swarm (extended abs.), in Lunar and Planetary Science XV, p.
780-781; also in Reports of Planetary Geology Program-1983: National
Aeronautics and Space Administration Technical Memorandum 86246, p. 37.
83. Shoemaker, E.M., and Wolfe, R.F., 1984, Crater ages, comet showers,
and the putative “Death Star” (abs.): Meteoritics, v. 19, p.
313.
84. Tanaka, K.L., Ulrich, G.E., and Shoemaker, E.M., 1984,
Magnetostratigraphy of the San Francisco volcanic field, Arizona (abs.):
Geological Society of America, Abstracts with Programs, Rocky Mountain
Section, p. 257.
85. Gillett, S.L., Kirschrink, J.L., Van Alstine, D.R., Lewis, R.E., and
Shoemaker, E.M., 1985, Paleomagnetism of upper Precambrian through Middle
Cambrian rocks from the Nopah Range, SE California (abs.): EOS, v. 66, p.
876.
86. Hut, P., Alvarez, W., Elder, W., Hansen, T.A., Keller, G., Shoemaker,
E. M., Weismman, P., 1985, Comet showers as possible causes of stepwise
mass extinctions (abs.): EOS, v. 66, p. 813.
87. Keller, G., D’Hondt, S., Onstott, T., Orth, C.J., Gilmore, G.S.,
Shoemaker, E.M., and Keigwin, L.D., Jr., 1985, Multiple late Eocene impact
events: stratigraphic, isotopic and geochemical data: Geological Society
of America, Abstracts with Programs, 1985, p. 626.
88. Shoemaker, E.M., and Shoemaker, C.S., 1985, Impact structures of
Western Australia (abs.): Meteoritics, v. 20, p. 754-756; also in Reports
of Planetary Geology and Geophysics Program 1985: National Aeronautics and
Space Administration Technical Memorandum 88383, p. 482-484.
89. Bus, S.J., Bowell, E., Shoemaker, E.M., and Kowal, C.T., 1986,
Photographic recovery of UCAS asteroids (abs.): American Astronomical
Society Bulletin, v. 18, p. 793.
90. Harris, A.W., and Shoemaker, E.M., 1986, Asteroid and comet collision:
response to the hazards (abs.): EOS, v. 67, p. 243.
91. Shoemaker, E.M., 1986, Hazards of asteroid and comet collision with
Earth (abs.): EOS, v. 67, p. 243.
92. Shoemaker, E.M., 1986, Satellites of Uranus (abs.): Geological Society
of America, Abstracts with Programs, 1986, p. 413.
93. Shoemaker, E.M., 1986, Geologic history of the Uranian satellites
(abs.): Geological Society of America, Abstracts with Programs, 1986, p.
749.
94. Shoemaker, E.M., and Shoemaker, C.S., 1986, Connolly Basin, a probable
eroded impact crater in Western Australia (extended abs.), in Lunar and
Planetary Science XVII, p. 97-798.
95. Shoemaker, E.M., Wolfe, R.F., and Shoemaker, C.S., 1986, Extinct
Jupiter-family comets and cratering rates on the galilean satellites
(extended abs.), in Lunar and Planetary Science XVII, p. 799-800.
96. Shoemaker, E.M., Wolfe, R.F., Bus, S.J., and Williams, J.G., 1986,
Proper elements and Mars-crossing depths of planet-crossing UCAS asteroids
(extended abs.), in Reports of Planetary Geology and Geophysics Program
1985: National Aeronautics and Space Administration Technical Memorandum
88383, p. 18-21
97. Schaber, G.G., Shoemaker, E.M., and Kozak, R.C., 1987, Is the Venusian
surface really old? (extended abs.), in Lunar and Planetary Science XVIII,
p. 874-875.
98. Schaber, G.G., Shoemaker, E.M., and Kozak, R.C., 1987, The surface age
of Venus: Applying the terrestrial cratering rate (extended abs.), in
Reports of Planetary Geology and Geophysics Program-1986: National
Aeronautics and Space Administration Technical Memorandum 89810, p.
405-407.
99. Schaber, G.G., Shoemaker, E.M., and Wolfe, R.F., 1987, The
geologically complex surface of Venus: Is it old or young? (abs.):
Geological Society of America Abstracts with Programs, p. 831.
100. Shoemaker, E.M., and Ostro, S.J., 1987, Thermally annealed ejecta in
icy regoliths: Source of the unusual radar echoes from Europa, Ganymede
and Callisto (abs), in American Astronomical Society Bulletin, v. 19, p.
631.
101. Shoemaker, E.M., and Shoemaker, C.S., 1987, Meteorite craters of
Western Australia (abs.): Geological Society of America Abstracts with
Programs, p. 842-843.
102. Shoemaker, E.M., and Shoemaker, C.S., 1987, Observations on the
magnitude-frequency distribution of Earth-crossing asteroids (extended
abs.), in Reports of Planetary Geology and Geophysics Program-1986:
National Aeronautics and Space Administration Technical Memorandum 89810,
p. 72-74.
103. Shoemaker, E.M., and Wolfe, R.F., 1987, Crater production on Venus
and Earth by asteroid and comet impact (extended abs.), in Lunar and
Planetary Science XVIII, p. 918-919; also in Reports of Planetary Geology
and Geophysics Program-1986: National Aeronautics and Space Administration
Technical Memorandum 89810, p. 402-408.
104. Champion, D.E., Lanphere, M.A., and Shoemaker, E.M., 1988, Multiple
polarity subchrons within the Brunhes and Matuyama polarity chrons (abs.):
EOS, v. 19, p. 1168.
105. Roddy, D.J., Shoemaker, E.M., Shoemaker, C.S., and Roddy, J.K., 1988,
Aerial photography and geologic studies of impact structures in Australia
(extended abs.), in Lunar and Planetary Science XIX, p. 990-991.
106. Shoemaker, C.S., and Shoemaker, E.M., 1988, The Palomar asteroid and
comet survey (PACS), 1982-1987 (extended abs.), in Lunar and Planetary
Science XIX, p. 1077-1078; also in Reports of Planetary Geology and
Geophysics Program, 1987: National Aeronautics and Space Administration
Technical Memorandum 4041, p. 52-54.
107. Shoemaker, E.M., 1988, Solar system roulette: Asteroid strikes and
comet showers (abs.): American Association for the Advancement of Science
1988 Annual Meeting Abstracts, p. 12.
108. Shoemaker, E.M., Roddy, D.J., Shoemaker, C.S., and Roddy, J.K., 1988,
The Boxhole meteorite crater, Northern Territory, Australia (extended
abs.), in Lunar and Planetary Science XIX, p. 1081-1082.
109. Shoemaker, E.M., and Shoemaker, C.S., 1988, Impact structures of
Australia (1987) (extended abs.), in Lunar and Planetary Science XIX, p.
1079-1080; also in Reports of Planetary Geology and Geophysics Program,
1987: National Aeronautics and Space Administration Technical Memorandum
4041, p. 425-427.
110. Shoemaker, E.M., and Shoemaker, C.S., 1988, The Spider impact
structure, Western Australia (abs.): Geological Society of America, 1988
Centennial Celebration, Abstracts with Programs, A 147.
111. Shoemaker, E.M., and Shoemaker, C.S., Wolfe, R.F., 1988, Asteroid and
comet, flux in the neighborhood of the Earth (extended abs.), in Global
Catastrophes in Earth History: An interdisciplinary conference on impacts,
volcanism, and mass mortality: Houston, Texas, Lunar and Planetary
Institute, p. 174-176.
112. Nishiizumi, K., Kohl, C.P., Shoemaker, E.M., Arnold, J.R., Lal, D.,
Klein, J., Fink, D., and Middleton, R., 1989, In situ 10Be-26Al exposure
ages at Meteor Crater, Arizona (extended abs.), in Lunar and Planetary
Science XX, p. 792-793.
113. Shoemaker, E.M., and Shoemaker, C.S., 1989, Geology of the Connolly
Basin impact structure, Western Australia (extended abs.), in Lunar and
Planetary Science XX, p. 1008-1009; also in Reports of Planetary Geology
and Geophysics Program 1988: NASA Technical Memorandum 4130, p. 586-587.
114. Shoemaker, E.M., Shoemaker, C.S., and Plescia, J.B., 1989, Gravity
investigation of the Connolly Basin impact structure, Western Australia
(extended abs.), in Lunar and Planetary Science XX, p. 1010-1011; also in
Reports of Planetary Geology and Geophysics Program 1988: NASA Technical
Memorandum 4130, p. 588-589.
115. Shoemaker, E.M., Shoemaker, C.S., and Wolfe, R.F., 1989, Asteroid and
comet flux in the neighborhood of the Earth (abs.), in Reports of
Planetary Geology and Geophysics Programs: NASA Technical Memorandum 4130,
p. 105-107.
116. Williams, J.G., Shoemaker, E.M., and Wolfe, R.F., 1989, Structure in
the Themis, Eos, and Koronis Families (extended abs.), in Lunar and
Planetary Science XX, p. 1207-1208.
117. Bowell, E., Holt, H.E., Levy, D.H., Innanen, K.A., Mikkola, S., and
Shoemaker, E.M., 1990, 1990 MB: A Mars Trojan (abs.): American
Astronomical Society Bulletin, v. 22, p. 1357.
118. Shoemaker, C.S., and Shoemaker, E.M., 1990, Survey for bright Trojan
asteroids (extended abs.), in Lunar and Planetary Science XXI, p.
1152-1153.
119. Shoemaker, C.S., Shoemaker, E.M., and Wolfe, R.F., 1990,
Investigation of the Trojan asteroids (extended abs.), in Reports of
Planetary Geology and Geophysics Program-1989: NASA Technical Memorandum
4210, p. 112-114.
120. Shoemaker, E.M., and Shoemaker, C.S., 1990, Proterozoic impact record
of Australia (extended abs.), in Abstracts for the International Workshop
on Meteorite Bombardment on the Early Earth: Lunar and Planetary Institute
Contribution No. 746, p. 47-48.
121. Shoemaker, E.M., Shoemaker, C.S., Nishiizumi, K., Kohl, C.P., Arnold,
J.R., Klein, J., Fink, D., Middleton, R., Kubik, P.W., and Sharma, P.,
1990, Ages of Australian meteorite craters (abs.): Meteoritics. v. 25, p.
409.
122. Shoemaker, E.M., Shoemaker, C.S., Wolfe, R.F., and Holt, H.E., 1990,
Earth-crossing asteroids, 1989 (extended abs.), in Lunar and Planetary
Science XXI, p. 1154-1156.
123. Shoemaker, E.M., Shoemaker, C.S., Wolfe, R.F., and Holt, H.E., 1990,
Earth-crossing asteroids update (extended abs.), in Reports of Planetary
Geology and Geophysics Program-1989: NASA Technical Memorandum 4210, p.
103-105.
124. Anderson, R.R., Hartung, J.B., Shoemaker, E.M., and Roddy, D.J.,
1991, New research core drilling in the Manson impact structure, Iowa: A
first look at the spectacular rocks formed at a K-T boundary impact site
(abs.): Geological Society of America, Abstracts with Programs, v. 23, no.
5, p. A402.
125. Attrep, M., Jr., Orth, C.J., Quintana, L.R., Shoemaker, C.S.,
Shoemaker E.M., and Taylor, S.R., 1991, Chemical fractionation of
siderophile elements in impactites from Australian meteorite craters
(abs.), in Abstracts of papers submitted to the Twenty-second Lunar and
Planetary Science Conference, part 1, Houston, March 18-22, 1991: Houston,
Lunar and Planetary Institute, p. 39-40; also in Reports of Planetary
Geology and Geophysics Program–1990: NASA Technical Memorandum 4300, p.
375-376.
126. Bowell, E., Muinonen, K., and Shoemaker, E.M., 1991, Discovery of
Earth-crossing asteroids. III. Observing strategy (abs.), in International
Conference on Near-Earth Asteroids Abstract Volume: San Juan Capistrano,
San Juan Capistrano Research Institute, p. 5.
127. Holt, H.E., Bowell, E., Shoemaker, C.S., and Shoemaker, E.M., 1991,
U.S. Geological Survey-Lowell Observatory asteroid survey: First results,
(abs.) in Abstracts for the International Conference on Asteroids, Comets,
Meteors 1991, Flagstaff, Arizona, June 24-28, 1991: Lunar and Planetary
Institute Contribution no. 765, p. 93.
128. Hut, P., Shoemaker, E.M., Alvarez, W., and Montanari, A., 1991,
Astronomical mechanisms and geologic evidence for multiple impacts on
Earth (extended abs.), in Abstracts of papers submitted to the
Twenty-second Lunar and Planetary Science Conference, part 2, Houston,
March 18-22, 1991: Houston, Lunar and Planetary Institute, p. 603-604.
129. Hut, P., Shoemaker, E.M., Alvarez, W., and Montanari, A., 1991,
Multiple impacts at Cretaceous-Tertiary boundary time: Break-up of a
single comet? (abs.), in International Conference on Near-Earth Asteroids
Abstract Volume: San Juan Capistrano, San Juan Capistrano Research
Institute, p. 16.
130. Levison, H.F., Shoemaker, E.M., and Wolfe, R.F., 1991, Mapping the
stability field of Jupiter Trojans (extended abs.), in Abstracts of papers
submitted to the Twenty-second Lunar and Planetary science Conference,
Houston, March 18-22, 1991: Houston, Lunar and Planetary Institute, p.
803-804; also in Reports of Planetary Geology and Geophysics
Program–1990: NASA Technical Memorandum 4300, p. 397-398.
131. Levison, H.F., Shoemaker, E.M., and Wolfe, R.F., 1991, Mapping the
stability field of Trojan orbits in the outer solar system (abs.), in
Abstracts for the International Conference on Asteroids, Comets, Meteors
1991, Flagstaff, Arizona, June 24-28, 1991: Lunar and Planetary Institute
Contribution no. 765, p. 135.
132. Muinonen, Karri, Bowell, Edward, Shoemaker, E.M., and Wolfe, R.F.,
1991, discovery of Earth-crossing asteroids. II. Modeling the sky-plane
distribution (abs.), in International Conference on Near-Earth Asteroids
Abstract Volume: San Juan Capistrano, San Juan Capistrano Research, p. 26.
133. Plescia, J., Shoemaker, E.M., and Shoemaker, C.S., 1991, Gravity
survey of the Mt. Toondina impact structure, South Australia (extended
abs.), in Abstracts of papers submitted to the Twenty-second Lunar and
Planetary Science Conference, part 3, Houston, March 18-22, 1991: Houston,
Lunar and Planetary Institute, p. 1079-1080; also in Reports of Planetary
Geology and Geophysics Program: NASA Technical Memorandum 4300, p.
384-385.
134. Shoemaker, C.S., Shoemaker, E.M., Wolfe, R.F., 1991, Systematic
survey for bright Jupiter Trojans (abs.), in Abstracts for the
International Conference on Asteroid, Comets, Meteors, 1991, Flagstaff,
Arizona, June 24-28, 1991: Lunar and Planetary Institute Contribution no.
765, p. 199.
135. Shoemaker, E.M., 1991, Geological and astronomical evidence for comet
impact and comet showers during the last 100 million year (abs.), in
Abstracts for the International Conference on Asteroids, Comets, Meteors
1991: Lunar and Planetary Institute Contribution no. 765, p. 199.
136. Shoemaker, E.M., Wolfe, R.F., and Shoemaker, C.S., 1991, Asteroid
flux and impact cratering rate on Venus (extended abs.), in Abstracts of
papers submitted to the Twenty-second Lunar and Planetary Science
Conference, part 3, Houston, Lunar and Planetary Institute, p. 1253-1254;
also in Reports of Planetary Geology and Geophysics Program–1990:
National Aeronautics and Space Administration Technical Memorandum 4300,
p. 389-390.
137. Shoemaker, E.M., Wolfe, R.F., Shoemaker, C.S., Bowell, E., Muinonen,
K., 1991, Discovery of Earth-crossing asteroids. I. History and goals for
a future program (abs.), in International Conference on Near-Earth
Asteroids Abstracts Volume: San Juan Capistrano, San Juan Capistrano
Research Institute, p. 31.
138. Steiner, M., Morales, M., and Shoemaker, E.M., 1991, Relative ages of
fossil caches, synchroneity of major lithology change, and formational
age, as determined by magnetostratigraphic correlation (abs.): American
Association of Petroleum Geologists Bulletin, Annual Convention Abstracts
v. 75, p. 676.
139. Nishiizumi, K., Kohl, C.P., Arnold, J.R., Caffee, M.W., Finkel, R.C.,
Southern, J., Shoemaker, E.M., and Shoemaker, C.S., 1992, Exposure
histories of desert sands using in situ produced cosmogenic nuclides
(abs.): EOS, v. 73, no. 14 supplement, p. 185.
140. Anderson, R.R., Hartung, J.B., Roddy, D.J., and Shoemaker, E.M.,
1992, Research core drilling in the Manson impact structure, Iowa
(extended abs.), in Papers presented to the International Conference on
Large Meteorite Impacts and Planetary Evolution, Aug. 31-Sept. 2, 1992,
Sudbury, Ontario, Canada: LPI Contribution No. 790, p. 2-3.
141. Shoemaker, E.M., 1992, Large-body impact is a geologic process
(abs.), in Geological Society of America Abstracts with Programs, 1992, p.
A134.
142. Shoemaker, E.M., and Izett, G.A., 1992, Stratigraphic evidence from
Western North America for multiple impacts at the K/T boundary (extended
abs.), in Papers submitted to the XXIII Lunar and Planetary Science
Conference: Lunar and Planetary Institute, Houston, Texas, p. 1293-1294.
143. Shoemaker, E.M., and Izett, G.A., 1992, K/T boundary stratigraphy:
Evidence for multiple impacts and a possible comet stream (extended abs.),
in Papers presented to the International Conference on Large Meteorite
Impacts and Planetary Evolution, Aug. 31-Sept. 2, 1992, Sudbury, Ontario,
Canada: LPI Contribution No. 790, p. 66-68.
144. Shoemaker, E.M., and Steiner, M.B., 1992, Reversely magnetized
breccia from the Manson Impact Structure, Iowa (abs.): EOS, October 27,
1992, Supplement, p. 336.
145. Anderson, R.R., Witzke, B.J., Hartung, J.B., Shoemaker, E.M., and
Roddy, D.J., 1993, Descriptions and preliminary interpretations of cores
recovered from the Manson Impact Structure (Iowa) (extended abs.), in
Abstracts of papers submitted to the Twenty-third Lunar and Planetary
Science Conference, Houston, March 15-19, 1993: Houston, Lunar and
Planetary Institute, p. 35-36.
146. Anderson, R.R., Witzke, B.J., Shoemaker, E.M., Roddy, D.J., and
Hartung, J.B., 1993, Research core drilling in the Manson impact
structure: Preliminary description of lithologic units (abs.), in
Geological Society of America, Abstracts with Programs, v. 25, p. .
147. Bowell, Edward, Levison, Harold F., Shoemaker, Eugene M., and
Weissman, Paul R., 1993, The Population of the Trans-Neptunian Region, in
Pluto & Charon, Flagstaff, Arizona, July 6-9, 1993, p. 13.
148. Roddy, D.J., and Shoemaker, E.M., 1993, The Manson Impact Crater:
Estimation of the energy of formation, possible size of the impacting
asteroid or comet, and ejecta volume and mass (extended abs.), in
Abstracts of papers submitted to the Twenty-third Lunar and Planetary
Science Conference, Houston, March 15-19, 1993: Houston, Lunar and
Planetary Institute, p. 1211-1212.
149. Shoemaker, E.M., Herkenhoff, K.E., and Gostin, V.A., 1993, Impact
origin of Upheaval Dome, Utah (abs.), in EOS, v. 74, October 26,
1993/Supplement, p. 388.
150. Shoemaker, C.S., Holt, H.E., Shoemaker, E.M., Bowell, E., and Levy,
D.H., 1993, The Palomar Asteroid and Comet Survey (PACS), 1983-1993
(abs.), in Abstracts for IAU Symposium 160: Asteroids, Comets, Meteors
1993, Belgirate (Novara), Italy, June 14-18, 1993: LPI Contribution No.
810, p. 269.
151. Shoemaker, E.M., and Nozette, Stewart, 1993, Clementine: An
inexpensive mission to the Moon and Geographos (extended abs.), in
Abstracts of papers submitted to the Twenty-third Lunar and Planetary
Science Conference, Houston, March 15-19, 1993: Houston, Lunar and
Planetary Institute, p. 1299-1300.
152. Shoemaker, E.M., Roddy, D.J., and Anderson, R.R., 1993, Research
program on the Manson Impact Structure, Iowa (extended abs.), in Abstracts
of papers submitted to the Twenty-third Lunar and Planetary Science
Conference, Houston, March 15-19, 1993: Houston, Lunar and Planetary
Institute, p. 1301-1302.
153. Shoemaker, E.M., and Shoemaker, C.S., 1993, The flux of periodic
comets near Earth, in Abstracts for IAU Symposium 160: Asteroids, Comets,
Meteors 1993, Belgirate (Novara), Italy, June 14-18, 1993: LPI
Contribution No. 810, p. 270.
154. Shoemaker, E.M., Shoemaker, C.S., and Levinson, H.F., 1993, Survey of
the Jupiter Trojans, in Abstracts for IAU Symposium 160: Asteroids,
Comets, Meteors 1993, Belgirate (Novara), Italy, June 14-18, 1993: LPI
Contribution No. 810, p. 271.
155. Shoemaker, E.M., Shoemaker, C.S., and Levy, D.H., 1993, Collision of
P/Shoemaker-Levy 9 with Jupiter (abs.), in American Astronomics Society
Bulletin, v. 25, p. 1042.
156. Steiner, M.B., and Shoemaker, E.M., 1993, The late Cretaceous Manson
impact structure (abs.). in EOS, v. 74, October 26, 1993/Supplement, p.
386.
157. Steiner, M.B., and Shoemaker, E.M., 1993, Two-polarity magnetization
in the Manson impact breccia (extended abs.), in Abstracts of papers
submitted to the Twenty-third Lunar and Planetary Science Conference,
Houston, March 15-19, 1993: Houston, Lunar and Planetary Institute, p.
1347-1348.
158. Vorder Bruegge, R.W., Davies, M.E., Horan, D.M., Lucey, P.G., Pieters,
C.M., McEwen, A.S., Nozette, S., Shoemaker, E.M., Squyres, S.W., and
Thomas, P.C., 1993, The Clementine Misson science return at the Moon and
Geographos (extended abs.), in Abstracts of papers submitted to the
Twenty-third Lunar and Planetary Science Conference, Houston, March 15-19,
1993: Houston, Lunar and Planetary Institute, p. 1469-1470.
159. Vorder Bruegge, R.W., and Shoemaker, E.M., 1993, The Clementine
Mission to the Moon and NEA 1620 Geographos (abs.), in American
Astronomical Society Bulletin, v. 25, p. 1091-1092.
160. Anderson, R.R., Witzke, B.J., Roddy, D.J., and Shoemaker, E.M., 1994,
Core drilling in the Manson impact structure provides abundant research
materials and new insights into the geology of a well-preserved complex
impact crater (abs.), in Abstracts with Programs, Geological Society of
America, 1994 Annual Meeting, October 24-28, 1994, Seattle, Washington, v.
26, no. 7, p. A-337.
161. Izett, G.A., Masaitis, V.L., Shoemaker, E.M., Dalrymple, G.B., and
Steiner, M.B., 1994, Eocene Age of the Kamensk Buried Crater of Russia
(extended abs.), in Papers Presented to New Developments Regarding the KT
Event and Other Catastrophes in Earth History, February 9-12, 1994:
Houston, Lunar and Planetary Institute, p. 55-56.
162. Pieters, C.M., Staid, M.I., Fischer, E.M., Shoemaker, G., and the
Clementine Science Team, 1994, Spectral Units of Large Lunar Craters from
Clementine Data (abs.), in Abstracts submitted to AGU, 1994 Spring
Meeting, May 23-27, Baltimore, Maryland, p. 222.
163. Robinson, M.S., and Shoemaker, E.M., 1994, Volcanic Materials of the
Schroedinger Basin: Timing and Emplacement Mechanisms (abs.), in EOS,
Transactions, American Geophysical Union, 1994 Fall Meeting, November 1,
1994, v. 75, no. 44, p. 399.
164. Roddy, D.J., Shoemaker, E.M., and Anderson, R.R., 1994, The Manson
Impact Structure Research Program: A summary of results (abs.), in
Abstracts with Programs, Geological Society of America, 1994 Annual
Meeting, October 24-28, 1994, Seattle, Washington, v. 26, no. 7, p. A-337.
165. Shoemaker, E.M., 1994, Clementine at Geographos (abs.), in Abstracts
submitted to AGU, 1994 Spring Meeting, May 23-27, Baltimore, Maryland, p.
222.
166. Shoemaker, E.M., 1994, Late Impact History of the Solar System
(abs.), in Abstracts submitted to AGU, 1994 Spring Meeting, May 23-27,
Baltimore, Maryland, p. 50.
167. Shoemaker, E.M., 1994, Update on the Impact Rates in the Jovian
System (abs.), in Icy Galilean Satellites Conference, February 1-3, 1994:
San Juan Capistrano, San Juan Capistrano Research Institute, p. 77.
168. Shoemaker, E.M., 1994, The Moon and Voyager: Highlights of Solar
System Exploration, Invited lecture at History Sessions, Astronomical
Society of the Pacific, June 28, 1994 Meeting, Flagstaff, Arizona at
Lowell Observatory.
169. Shoemaker, E.M., 1994, Ignorance of History is Bliss (abs.), in
Abstracts with Programs, Geological Society of America, 1994 Annual
Meeting, October 24-28, 1994, Seattle, Washington, v. 26, no. 7, p. A-281.
170. Shoemaker, E.M., 1994, Clementine at the Moon (abs.), Bull. America
Astronomical Soc., v. 26, p.1426.
171. Shoemaker, E., and Cheng, A.F., 1994, Near Earth Asteroid Returned
Sample (NEARS) (abs.), in Book of Abstracts: IAA International Conference
on Low-Cost Planetary Missions at The Johns Hopkins University, Laurel,
Maryland, April 12-15, 1994, p. 6.
172. Shoemaker, E.M., and Shoemaker, C.S., 1994, The Crash of
P/Shoemaker-Levy 9 into Jupiter and its Implications for Comet Bombardment
on Earth (extended abs.), in Papers presented to New Developments
Regarding the KT Event and Other Catastrophes in Earth History, February
9-12, 1994: Houston, Lunar and Planetary Institute, p. 113-114.
173. Shoemaker, E.M., Hassig, P.J., and Roddy, D.J., 1994, Impact Plume
Dynamics on Jupiter (abs.), in EOS, Transactions, American Geophysical
Union, 1994 Fall Meeting, November 1, 1994, v. 75, no. 44, p. 402.
174. Shoemaker, E.M., Robinson, M.S., and Eliason, E.M., 1994, Age
Relation of the Schroedinger Multiring Basin Determined from Clementine
Images (abs.), in EOS, Transactions, American Geophysical Union, 1994 Fall
Meeting, November 1, 1994, v. 75, no. 44. p. 399.
175. Steiner, M.B., and Shoemaker, E.M., 1994, The Late Cretaceous Manson
Impact Structure (abs.), in EOS, Transactions, American Geophysical Union
Spring Meeting, May 23-27, Baltimore, Maryland, v. 75, no. 16, Supplement
p. 123.
176. Steiner, M. and Shoemaker, E., 1994, Two-polarity magnetization of
the Manson impact breccias (abs.), in Abstracts with Programs,Geological
Society of America, 1994 Annual Meeting, October 24-28, 1994, Seattle,
Washington, v. 26, no. 7, p. A-338.
177. Weaver, H.A., Noll, K.S., Storrs, A.D., Smith, T.E., A’Hearn, M.F.,
Arpigny, C., Feldman, P.D., Boice, D.C., Stern, A., Lamy, P.L., Larson,
S.M., Levy, D.H., Scotti, J.V., Marsden, B.G., Meech, K.J., Shoemaker, C.S.,
Shoemaker, E.M., Sekanina, Z., Trauger, J.T., Yeomans, D.K., and Zellner,
B., 1994, HST monitoring of Comet P/Shoemaker-Levy 9 (abs.), Bull.
American Astronomical Soc., v. 26, p. 1564.
178. McEwen, A.S., and Shoemaker, E.M., 1995, Two classes of impact basins
on the Moon (extended abs.), in Abstracts of papers submitted to the
Twenty-sixth Lunar and Planetary Science Conference, Lunar and Planetary
Institute, Houston, Texas, p. 935-936.
179. Robinson, M.S., and Shoemaker, E.M., 1995, Clementine UVVIS high
resolution spectral measurements of lunar local dark mantle deposits(abs.)
in, Abstracts with Program, Geological Society of America, 1995 Annual
Meeting, November 6-9, 1995, New Orleans, Louisiana, p. A-289.
180. Roddy, D.J., and Shoemaker, E.M., 1995, Meteor Crater (Barringer
Meteorite Crater), Arizona: Summary of impact conditions (abs.), in
Meteoritics, 58th Annual Meeting, Meteoritical Society, Washington, D.C.,
September 11-15, 1995, v. 30, no. 5, p. 567.
181. Roddy, D.J., Shoemaker, E.M., and Anderson, R.R., 1995, Manson impact
structure research program: Summary through January 1995 (extended abs.),
in Abstracts of papers submitted to the Twenty-sixth Lunar and Planetary
Science Conference, Lunar and Planetary Institute, Houston, Texas, p.
1181-1182.
182. Schmitt, H.H., Griffin, M.D., Kulcinski, G.L., and Shoemaker, E.M.,
1995, Interlune-One: A scientific mission across the surface of the Moon
(abs.), in Abstracts of papers submitted to the Twenty-sixth Lunar and
Planetary Science Conference, Lunar and Planetary Institute, Houston,
Texas, p. 1241-1242.
183. Shoemaker, E.M., and Robinson, M.S., 1995, Clementine observations of
melt rocks and volcanic materials in the Schršdinger Basin (extended
abs.), in Abstracts of papers submitted to the Twenty-sixth Lunar and
Planetary Science Conference, Lunar and Planetary Institute, Houston,
Texas, p. 1297-1298.
184. Shoemaker, E.M., Roddy, D.J., Moore, C.B., Pfeilsticker, R., Curley,
C.L., Dunkelman, T., Kuerzel, K., Taylor, M., Shoemaker, C., and Donnelly,
P., 1995, Impact crater identified on the Navajo Nation near Chinle,
Arizona (abs.), in Meteoritics, 58th Annual Meeting, Meteoritical Society,
Washington, D.C., September 11-15, 1995, v. 30, p. 578-579.
185. Kargel, J.S., Coffin, P., Kraft, M., Lewis, J.S., Moore, C., Roddy,
D., Shoemaker, E.M., and Wittke, J.H., 1996, Systematic collection and
analysis of meteoritic materials from Meteor Crater (extended abs.), in
Abstracts of papers submitted to the Twenty-seventh Lunar and Planetary
Science Conference, Lunar and Planetary Institute, Houston, Texas, p.
645-646.
186. Kriens, B. J., Herkenhoff, K.E., and Shoemaker, E.M., 1996, Structure
and kinematics of a complex crater, Upheaval Dome, SE Utah (abs.), in
Abstracts with Programs, 1996 Annual Meeting, Geological Society of
America: Denver, Colorado, October 28-31, 1996, p. A-108.
187. Nozette, S., Lichtenberg, C.L., Spudis, P. Bonner, R., Ort, W.,
Malaret, E., Robinson, M., and Shoemaker, E., 1996, Clementine bi-static
radar experiment: Preliminary results (abs.), in Abstracts of papers
submitted to the Twenty-seventh Lunar and Planetary Science Conference,
Lunar and Planetary Institute, Houston, Texas, p. 967.
188. Robinson, M.S., Shoemaker, E.M., and Hawke, B.R., 1996, Spectral
heterogeneity of lunar local dark mantle deposits (extended abs.), in
Abstracts of papers submitted to the Twenty-seventh Lunar and Planetary
Science Conference, Lunar and Planetary Institute, Houston, Texas, p.
1087-1088.
189. Shoemaker, E.M., 1996, Exploration of near-earth asteroids (abs.), in
1996 AAAS Annual Meeting and Science Innovation Exposition: Baltimore,
Maryland, Feb. 8-13, 1996, p. A-52.
190. Shoemaker, E.M., 1996, Impact sites of comets and asteroids (abs.) in
1996 AAAS Annual Meeting and Science Innovation Exposition: Baltimore,
Maryland, Feb. 8-13, 1996, p. A-159-A160.
191. Shoemaker, E.M., 1996, The Age of Europa’s Surface (abs.), in Europa
Ocean Conference, Capistrano Conference No. 5, San Juan Capistrano
Research Institute, San Juan Capistrano, California, Nov. 12-14, 1996, p.
65-66.
192. Shoemaker, E.M., Nishiizumi, K., and Kohl, C.P., 1996, The frequency
of impact events similar in energy to the Tunguska event (abs.), in
International Workshop Tunguska 96: Bologna, Italy, July 15-17, 1996, p.
23.
193. Shoemaker, E.M. and Shoemaker, C.S., 1996, The impact record of
Australia (abs.), in Geological Society of Australia, Abstracts No. 41: 13
Australian Geological Convention, Canberra, Feb. 1996, p. 391.
194. Shoemaker, E.M. and Shoemaker, C.S., 1996, Small body collisions with
the Earth (abs.), in Asteroids, Comets, Meteors COSPAR Colloquium 10:
Versailles, France, July 8-12, 1996, p. 2.
195. Shoemaker, E.M. and Shoemaker, C.S., 1996, Possible variations in the
long-term comet flux and their correlation with global climate (abs.),
EOS, v. 77, no. 22, Supplement, P42A.
196. Shoemaker, E.M. and Uhlherr, H.R., 1996, Stratigraphic relations of
tektites and Pleistocene uplift in the Port Campbell Embayment, Victoria
(abs.), EOS, v. 77, no. 22, Supplement, p. 42A2.
197. Shoemaker, E.M., 1997, Long-term variations in the impact cratering
rate on Earth (abs.), in Meteorites: Flux with Time and Impact Effects, 18
– 19th February, 1997, Geol. Soc. London, Burlington House, London: p. 41.
198. Shoemaker, E.M., 1997, How young is Europa’s surface? (abs.), in 1997
American Association for the Advancement of Science Annual Meeting and
Science Innovation Exposition, 13-18 February, Seattle, Washington: p.
A-76.
199. Shoemaker, E.M., and Shoemaker, C.S., 1997, Notes on the geology of
Liverpool Crater, Northern Territory, Australia (extended abs.), in
Abstracts of papers submitted to the twenty-eighth Lunar and Planetary
Science Conference, Lunar and Planetary Institute, Houston, Texas, March
17-21, 1997, p. 1311-1312.
200. Shoemaker, E.M., and Shoemaker, C.S., 1997, Glikson, a probable
impact structure, Western Australia (extended abs.), in Abstracts of
papers submitted to the twenty-eighth Lunar and Planetary Science
Conference, Lunar and Planetary Institute, Houston, Texas, March 17-21,
1997, p. 1309-1310.
201. Shoemaker, E.M. and Shoemaker, C.S., 1997, Dispersion of stones by
human transport: A Solution to the enigma of australite
“stratigraphic ages” (abs.), in American Geophysical Union 1997
Spring Meeting, EOS, v. 78, no. 17 Supplement, p. 5201.
202. Shoemaker, E.M., and Wynn, J.C., 1997, Geology of the Wabar meteorite
craters, Saudi Arabia (extended abs.), in Abstracts of papers submitted to
the twenty-eighth Lunar and Planetary Science Conference, Lunar and
Planetary Institute, Houston, Texas, March 17-21, 1997, p. 1313-1314.
Gene Shoemaker at his office in Flagstaff, Arizona
Gene Shoemaker
The impact of comets has profoundly influenced the story of life." -- Gene Shoemaker
"Every time a giant comet strikes the Earth, the dice of evolution are thrown again." David Levy, Comets: Creators and Destroyers;Touchstone Books. 1998
1969 - Caltech where he began the search for Earth-crossing asteroids and where he advanced the idea that sudden geologic changes can arise from asteroid strikes and that asteroid strikes are common over geologic time periods.
October 17, 1974 - E. F. Helin discovers a minor planet and names it 2074 Shoemaker.
1993 - Co-discovered Comet Shoemaker–Levy 9 using the 18" Schmidt camera at Palomar Observatory. This comet was unique in that it provided the first opportunity for scientists to observe the planetary impact of a comet. Shoemaker–Levy 9 collided with Jupiter in 1994.
18 July 1997 - A road accident near Alice Springs ends the
life of Eugene M. Shoemaker, the 20th century's greatest planetary
geologist. Coroner's Report
06 Jan 1998 - Aboard an Athena rocket "Lunar
Prospector" is launched to the Moon carrying a small amount of Gene's
cremains. It's mission: to map the moon for elements. It's discovery:
confirmation of water/ice in craters at the lunar poles.
31 July 1999 - Impact of "Lunar Prospector"
occurred at 09:52:02 GMT, 02:52am Pacific Daylight Time.
Artist Concept: Near Shoemaker at Eros
February 2000 - The Near Earth Asteroid Rendezvous space probe to asteroid 433 Eros was renamed "NEAR Shoemaker" in his honor. After a year of orbital study, it landed on the asteroid.
"We will now discuss in a little more detail the Struggle for Existence." Darwin
The Precambrian
Stand still you ever-moving spheres of heaven,
That time may cease, and midnight never come.
--Christopher Marlowe (1564 - 1593)
(This period makes up approximately 7/8ths of the Earth's history!)
Prior to 3.8 billion years ago - Hadrean Era
Protoplanetary diskElements are added to the planet
The Solar System and Earth are born from a churning nebula of dust and gas and heavy elements derived from an earlier supernova in the galactic neighbourhood. When the sun ignited a violent shock hurled most of the stellar debris into deep space. Proplyds, containing organic molecules, condense even further to form the planetary system surrounding our star. The sun was cooler, radiating 25% less energy than today.
3.8 to 2.5 billion years ago - Archean Era
stromatolite
The rate of heat production by the breakdown of radioactive isotopes was several times greater than today, but eventually, the Earth's crust begins to cool and attains some stability and rigidity. Crust building activity such as volcanoes begin to form bits of continental rock. The earth is spinning faster upon its axis. Oceans are forming, condensing from atmospheric vapour.
Organic compounds called lipids exist in seabeds. Organic information processing has begun and blue-green algae and bacteria evolve. The first primitive cells were of the Prokaryotic type and probably obtained energy through the splitting of simple available organic compounds. Filamentous and spheroidal microfossils are found in many Precambrian sediments. Prokaryotic cell organisms, incapable of cell division, are small, ca 10 microns, and have no cell nucleus.
The first cells were probably primitive bacterial and algal heterotrophs; that is they fed off energy from organic compounds (not the atmospheric carbon dioxide). These cells diversified and became autotrophs, or cells able to utilize energy from atmospheric carbon dioxide and water. Cyanobacteria grow in colonies large enough to see and in some places they formed stromatolites. They are aquatic and photosynthetic.
Organisms which feed off the carbon dioxide in the atmosphere begin to release oxygen into the atmosphere and ocean. This triggers a change in the chemistry of the ocean and atmosphere from a carbon dioxide-rich mixture eventually to the present-day oxygen-rich atmosphere.
Proterozoic rocks become important sources of metallic ores, notably of iron, gold, copper, uranium, and nickel.
Regional impacting continues.(?) 1x100,000 years = 27,000 1km impacts in 2.7 billion years
Some polar glaciation.
The Moon has become geologically inactive.
2.5 billion to 544 million years ago - Proterozoic Era
The moon is receding from the planet. It will separate nearly 100,000 kms in the next billion years.
The diversity of simple marine organisms. Stromatalites become important as the first reefs.
1.4 billion years ago Eukaryotic cell organisms develop, either by an infolding of the cell wall to form internal structures or by an invasion of smaller specialized procaryotes which then form the internal structure of the eukaryote cell. This promotes greater genetic variation and faster evolution. Eukaryotes take over as the dominant life form. The atmosphere is increasingly oxygenic yet still only 1% of oxygen levels in the modern era.
1.1 billion years ago, Rodinia, the first stable supercontinent forms then 750 million years ago Rodinia breaks into three pieces
1.0 billion years ago begins the greatest glaciation period the Earth has ever experienced. About 650 million years ago 70% of the dominant Precambrian flora and fauna perished in the first great extinction.
600 million years ago The continental pieces of Rondinia come back together in a big crunch known as the Pan-African orogeny (mountain building event). The new supercontinent is known as Pannotia.
The first multi-celled animals (metazoa) evolved, types of jellyfish and worms without skeletons or shells. In an area now known as the Ediacara Hills of South Australia an assortment of sea animals had evolved highly differentiated systems of muscles, nerve cells and food-gathering and sexual organs. Fossils of similar life forms have also been found in Canada and Africa. Some members of the Ediacara biota survived the extinction and become the ancestors of the life forms which evolve during the next era. Ediacara
Earthshine
Cambrian
Burgess Shale, Hallucinagenia ... locomotion plus.545 million years ago "Cambrian Explosion." All life is still in water but begins to proliferate and diversify. Animals with hard shells and backbones skeletons) appear in marine environments. Skeletons serve as an adaptive breakthrough, support for muscles, protection against environment and predators, and aid in locomotion, allowing preferential survival and niche exploitation. Trilobites andsome mollusks appear in great numbers. Trilobites made up 80% of animal species. Animals with eyes first appear.
Trilobite
550 million years ago Pannotia breaks up into several small fragments, Laurentia (the core of the modern era North America), Baltica (Northern Europe), and Siberia and one large piece (now China, India, Africa, South America and Antarctica) known as Gondwana. Atmospheric oxygen levels are 10% of modern era levels.
515 million years ago Burgess Shale fauna is alive, these may have been the first animals to use body colour to repel predators. Pikaia evolves, the world's first known chordate, possibly the ancestor of all other vertebrates.
Pikaia of the Burgess Shale
Four mass extinctions occurred during the course of the Cambrian.
Snowball Earth?
The two most accepted current hypotheses for the Cambrian extinction are: glaciation in the early Ordovician and cooling and depletion of oxygen in marine waters.
Ordovician
505 - 438 million years ago
A crinoid is not a plant, but an animal that learned to plant its feet on the seafloor.
From the Early to Middle Ordovician, the earth experienced a milder climate in which the weather was warm and the atmosphere contained a lot of moisture. In the seas rugose and tabulate forms of coral reefs evolved and a variety of new types of life, including cephalopods, bryozoans, crinoids, graptolites, gastropods, and bivalves flourished. Life begins grasping outward for its food. Ordovician communities displayed a higher ecological complexity than Cambrian communities due to the greater diversity of organisms. The diversity of sea animal genera may have increased due to active mountain building activity when more nutrients and environmental isolation fueled development of species, tectonic activity contributing to life's energy needs. On land types of algae and fungus begin to evolve.
Ordovician sea
Ordovician Mass extinction - 440 - 450 million years ago was the second greatest mass extinction of marine life in the history of Earth, caused the disappearance of one third of all brachiopod and bryozoan families, as well as numerous groups of conodonts, trilobites, and graptolites. Much of the reef-building fauna was also decimated. In total, more than one hundred families of marine invertebrates perished in this extinction.
Silurian
438 - 408 million years ago
Silurian crinoids
Some of the Rodinian mass is torn apart and moved to equatorial regions. The remains of Rodinia, Gondwana, rotated clockwise and moved northward to collide with Laurasia --
Baltica and the attached micro continent Avalonia begin colliding with North America in scissors fashion [north to south] to form the Caledonian-Acadian orogeny.
Silurian Map
Rise in sea levels due to polar glacier melts. Estuaries became more productive and diverse, while freshwater habitats were being colonized. Rapid spread of jawless fish and first land animals that feed on terrestrial algae and fungus.
Pterygolepis - Anaspida
Devonian
408 - 360 million years ago
Age of a transforming biosphere.
The bony fishes of the seas diversified and the world was dominated by reef builders such as the stromatoporoids, and corals, and some of the world's largest reef complexes were built. Early Devonian saw freshwater branchiopods appear in streams. The variety of land plants increased dramatically and the first land animals appear. Tracheophyta, vascular plants, evolved along water's edge supporting a greater diversity of invertebrates like spiders and scorpions. At mid-Devonian the first jawed fish appear and the first forests arose. By the Late Devonian, plants were sufficiently evolved to colonize drier land and the early tetrapods walked the Earth.
Hynerpeton - early tetrapod
Appalachian mountains form.
Atmospheric oxygen reaches modern era levels.
Late Devonian Mass Extinction at the Frasnian - Famennian boundary. Evidence supporting an episode of global cooling suggests that warm water marine species were the most severely affected when sea levels lowered triggered by a glaciation event on Gondwana.
Moresnetia zalesskyi fossil of late Devonian Hans Steur
Archaeognatha wingless insect of the Devonian by Wayne P. Maddison
Gosslingia breconensis fossil of early Devonian
Carboniferous
360 - 286 million years ago
Carboniferous forest
The forests were composed of giant club mosses, tree ferns, and horsetails, some of which towered more than 30m (99ft) above the forest floor. The most abundant of the modern era coal supplies accumulated by the respiration of these forests.
The first reptiles evolve. Westlothiana, a tiny creature, contains many intermediate characters between primitive tetrapods and true
amniotes. The amniotic egg allowed Synapsida and Sauropsida the ancestors of birds and mammals, to breed away from water, opening up vast new environments for habitation. Insects were evolving such as the dragonflies with 71cm (28in) wingspans, and cockroaches over 10cm (4in) long. In the rivers and in the seas, the jawed, bony fish had largely replaced the jawless, heavily armored fish.
Westlothiana
Permian
286 - 245 million years ago
functional types of amniote skulls
Two ancestral amniotes flourished, the Sauropsida, reptiles lie the labyrinthodonts and future dinosaurs and Synapsida which includes pelycosaurs like the "finback" dimetrodon and future mammals.
The continental islands move together to form the massive landmass of Pangea. Ocean currents moderate temperate coastal areas, and the continental interior is dry. Prolonged volcanism forms the terrace-like formations known as the Siberian Traps. The effects of the massive eruption would have made the world dark and increased sulfur dioxide, cooling the planet, then producing carbon-dioxide in the atmosphere, heating the planet. The seas regressed. Permian extinction brings an end to 95% of all ocean-dwelling species and at least 70% of land-dwelling vertebrates. Bye, bye trilobytes. The cause of the Permian extinction was either an asteroid or comet impact big enough to crack the Earth's crust causing the prolonged volcanism at the Siberian Traps. Questions whether impacts cause volcanic events are just now being answered.
Dimetrodon - mammilian ancestor
LENGTH: 250 centimeters (8 feet) HEIGHT: 90-120centimeters (3-4 feet) WEIGHT: 70 kilograms (150 pounds) DIET: Other animals
The Mesozoic
286 - 245 million years ago - The Triassic
The continental mass was warm, but cut off from rain-bearing ocean winds, inland regions formed vast deserts.
Extreme volcanism and tectonic activity along the western coast of North America results in the building of the western cordillera. In the seas ammonoids have replaced the trilobites of the Permian. In the early Triassic they are characterized by subdued shell ornamentation but by the end of the period the shells become more decorative. Marine animals flourished in the warm, tropical oceans, in particular the ammonoids, brachiopods, and echinoderms.
In the seas ammonoids have replaced the trilobites of the Permian. In the early Triassic they are characterized by subdued shell ornamentation but by the end of the period the shells become more decorative. Marine animals flourished in the warm, tropical oceans, in particular the ammonoids, brachiopods, and echinoderms.
Dicynodont
A mammal-like reptile
Ferns and horsetail plants grew near water, tree-like cycadeoids and cycads were the tallest plants. Ginkoes and swamp cypress had evolved. Conifers evolved in upland dry areas. For most of this period the dominant land animal is a mammal-like reptile, aquatic, herbivorous therapsids, like the Dicynodonts. Their posture was sprawling and their size was from one to three meters in length.
Dinosaurs begin to evolve from the most quadrupedal reptiles, thecodonts. In the late Triassic the first known predatory dinosaurs are the Staruikosaurids, the Herrerasurids and the Coelophysids. Mouse-like prototherian mammals appear.
A thecodont,
forerunner of the dinosaurs
A volcanic crisis at the end of the Triassic period heats up the planet and delivers basalt lavas across a 7 million km area. Pangea (All Earth) begins to break up into Laurasia (North America, Europe, and Asia) and Gondwana (South America, Africa, India, Antarctica and Australia.)
208 - 150 million years ago - The Jurassic
The rifting of the supercontinents continue. The Atlantic Ocean opens and shallow seas covered much of North America. Climates were warm and wet.
The primitive dinosaurs which survived the extinctions at the end of the Triassic begin a 130 million year dominance of the planet. Evolutionary innovation and complexity provide lifeforms with new technologies; getting upright and taking the skull of an animal above ground level, ie: HerraRaptor. Eventually, the evolution of the dinosaur would produce a diversity of hundreds of species, many who socialized in communities.
It is the age of the size counts. Great plant-eating sauropods and predatory theropods get bigger. The oceans are full of fish, squid, and coiled ammonites, plus great ichthyosaurs and long-necked plesiosaurs.
Pterosaur
Pterosaurs, the first flyers, are thought to be derived from a bipedal, cursorial (running) archosaur in the late Triassic period. Primitive mammals, marsupials, and cranes have evolved. Flowering plants begin to appear as do butterflies.
149 - 65 million years ago - The Cretaceous
Temperatures on Earth were warm. Flora and fauna thrived around polar regions as well as the equator. The land was covered with forests and a large inland sea divided the North American Continent.
40 ft, 10 ton reptilian sea monster, Mosasaur were the largest marine predator.
mosasaur
A collision between a cosmic rock and the moon 110 mya forms Copernicus Crater.
Deccan basalts in India may have played a role in the extinction of the dinosaurs. Most of the basalt erupted between 65 and 60 million years ago.
gravity map of the chicxulub impact
The last day of the Mesozoic. Chixilub KT impact. Oblique @30% 6 km/sec 10-15 km mass=? Comet or Asteroid? Impact energy would be 1000 times greater than exploding all of the human nuclear weapons all at once. Much of the impact energy was transferred to the atmosphere and a sudden poisonous haze cooled the planet 3 - 7 degrees. Immense acid rain fell onto the land and ocean shutting down photosynthesis. A sudden a but short darkening of the skies caused the extinction of 7 out of 10 species. Rule of the Reptile Ends.
Over the next era, the planet would warm again and spores would colonize a decimated low diversity environment. The small mammals, terrabirds, some aquatic life, and insects were the only survivors able to adapt to the new environment.Earth and Moon from Apollo 11
The Cenozoic
65 million years ago ... life pervades again - Tertiary
Fragmentation of continental landmasses continue. Rifts separated Africa from South America and then Australia from Antarctica. Gondwanaland ceases to exist as a supercontinent. The Atlantic Ocean widens. Africa moved northward towards Eurasia, closing the Tethys Ocean and raising the Alps. India collides with Asia, forming the Himalayan mountains. Australia rifts free of what is left of Gondwanaland and becomes an Island Continent drifting northwards towards Asia.
Sea-levels fall and expose dry land in much of inland North America, Africa, and Australia. South America has separated becoming an island with its own unique evolution of animals.
At the beginning of this era the world was almost devoid of large terrestrial animals. There wasn't an animal larger than 30 kgs, all with small brain cavities, and archaic features. However, it was only 10 million years before large animals were roaming the continents taking up the ecological niches left vacant by the extinction of the dinosaurs.
Mesonychia, from hooved animals
Mesonychia, derived from hoofed mammals, were the first group of mammals to become meat eaters, they were the likely dominant land predators of the paleocene epoch.
49 million years ago
Kamensk meteorite impact, Russia, results in a crater 25 kms in diameter.
40 million years ago
Azuara meteorite impact, Spain, results in a crater 30 kms in diameter.
38 million years ago
The continents arrive their present positions.
Mistastin meteorite impact, east coast of North America, results in a crater 28 kms in diameter.
35 million years ago
Chesapeake Bay meteorite impact, east coast of North America, results in a crater 85 kms in diameter. Popigai meteorite impact, Russia, results in a crater 100 kms in diameter.
25 million years ago
Logancha meteorite impact, Russia, results in a crater 20 kms in diameter.
20 million years ago
Haughton meteorite impact, in the Canadian north, results in a crater 24 kms in diameter.
Chimapanzee
15 million years ago
Ries meteorite impact, in Europe, results in a crater 24 kms in diameter.
10 million years ago
Last common ancestor of hominids and apes. Ramapithecus, once thought to be a human ancestor had evolved, different from apes mainly in skull innovations, but some evidence suggests that Ramapithecus is related closer to orangutans than humans.
5 million years ago
Kara-Kul meteorite impact, Tajikistan, results in a crater 52 kms in diameter.
4.4 million years ago
Ardipithecus ramidus, a forest dweller, four foot tall bipedal.
3.5 million years ago
Lucy walks the Earth (Australopithecus afarensis).
1 million years ago
500,000 years ago
Archaic forms of Homo sapiens first appear.
250,000 years ago
Neanderthals appeared in Europe.
200,000 years ago
Homo Sapiens come out of Africa and may have interbred with Neanderthals
50,000 years ago
Impact in Arizona forms Meteor Crater
20,000 years ago
Neanderthals disappear.
Homo sapiens paint star maps on the Altimera cave walls in France.
10,000 years ago
Last great ice age. When the planet's northern polar cap extended over northern Europe, the moist Mediterranean air was pushed into equatorial regions by a dominant high-pressure system over the icy cap. The climate of the Nile, and Tigris and Eurphrates became considerably more comfortable for human habitation than it is today. Modern human civilization begins.
6,000 years ago
Writing is developed in Sumeria.
4,000 years ago
A massive earthquake in Sodom and Gohmorrah. Hebrews suspect it is the retribution of God. It is also the age of Noah's flood when according to scripture the Earth became a less habitable place. Mammoths become extinct, but for their frozen remains.
200 years ago
The planet's human population reaches one billion.
140 years ago
Darwin's "Origin of Species" Debate in England. Age of the Earth controversies reaches a fevered pitch.
100 years ago
Tunguska impact
Coates and Marsh uncover 125 species of dinosaurs
50 years ago
Neil Armstrong and Buzz Aldrin walk on the moon.
Voyager 1 & 2 are launched on missions of Solar System Exploration
1999
Chandra X-Ray Observatory
Chandra Xray Observatory is launched.
