Archive for Planetary Science Research Discoveries | Planetary Science and Resources Discoveries | PSRD (original) (raw)
Planetary scientists sharing ideas and discoveries.
Planetary Science and Resources Discoveries (PSRD) is an educational site sharing the latest research on the nature and origin of the Moon, meteorites, asteroids, planets, and other materials in our Solar System, and on identifying potential resources on those bodies that could be tapped for the benefit of people on Earth. Original support came from the Planetary Science Division of NASA's Science Mission Directorate and Hawai'i Space Grant Consortium. This site is a vital link for what's new in planetary and space sciences, space resources exploration, and learning how science works.
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DATE POSTED
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17 SEPT 2022
Detailed Microanalysis of One Lunar Rock Provides Insight into Formation of the Entire Lunar Magnesian Suite
by G. Jeffrey Taylor
The distribution of phosphorous in olivine and sodium in plagioclase in lunar rock 76535 suggest that its formation may have involved reaction between magma ocean products and magma formed by partial melting in the lower crust.
17 DEC 2021
Remembering Edward R. D. Scott (1947-2021)
by G. Jeffrey Taylor and Linda M. V. Martel
Ed was a leading authority on the geochemistry, mineralogy, and petrology of iron meteorites.
03 JUNE 2021
Remembering Ross Taylor (1925-2021)
by G. Jeffrey Taylor
Over his distinguished and creative career Ross made significant contributions to planetary geochemistry and solar system evolution.
25 MAY 2021
Heating Meteorites to Understand Exoplanet Atmospheres
by G. Jeffrey Taylor
Heating carbonaceous chondrites in a vacuum oven provides constraints on the origins of the atmospheres of Earth-like planets around other stars.
03 MAY 2021
Seeing What We Have Never Seen Before: Low-Frequency Radio Astronomy from the Moon
by G. Jeffrey Taylor
Low-frequency radio observations from the radio-quiet lunar farside will allow astronomers to probe the universe from its mysterious dark ages after the Big Bang, to the nature of the magnetospheres of planets around other stars and the outer planets in our Solar System, and to better understand the causes of explosive release of plasma from the Sun's corona.
24 MAR 2021
The Tarnished Moon
by G. Jeffrey Taylor
Remote sensing observations reveal the presence of ferric iron in the form of the mineral hematite at high latitudes on the Moon, possibly the product of reaction of ferrous iron on the Moon with oxygen from the Earth's upper atmosphere.
1 MAY 2020
Explaining the Compositional Heterogeneities of the Martian Mantle by Late Accretion of Large Projectiles
by G. Jeffrey Taylor
Compositional variations in the Martian mantle may be caused by addition of a few large impactors after planet construction was mostly finished.
31 MAR 2020
Remembering William A. Cassidy (1928-2020)
by Linda M. V. Martel
Bill began and led the Antarctic Search for Meteorites program from 1976 to 1995, which is ongoing and widely regarded as resulting in the single most important collection of research meteorites in the world.
24 MAR 2020
Hydrogen Isotopes in Small Lunar Samples Provide Clues to the Origin of the Earth and Moon
by G. Jeffrey Taylor
Small samples of igneous rocks from the Moon have low deuterium/hydrogen ratios, indicating that some planetary bodies involved in the formation of the Earth and Moon trapped gas from the solar nebula.
9 MAR 2020
Greatest Show on Venus: Lavas are Hot and Fresh Out of the Mantle
by David Trang
Spectral observations of the surface of Venus and experiments determining rates of alteration due to the hot Venusian atmosphere indicate that some basalts on the planet's hot surface formed within the past several years.
14 NOV 2019
Using the Resources of the Moon to Expand Earth's Economic Sphere
by G. Jeffrey Taylor
Lunar and material scientists, engineers, and entrepreneurs discussed using lunar resources to enable lunar settlement and utilization.
19 JULY 2019
Lunar Samples Collected Up There and Down Here
by Linda M. V. Martel
Apollo lunar samples and lunar meteorites help us understand not only the Moon and Earth, but also fundamental processes in our Solar System.
16 JULY 2019
Scientific Discoveries from the Apollo 11 Mission
by G. Jeffrey Taylor
The Apollo 11 mission showed that the Moon formed hot, that it was magmatically active for at least 800 million years, and that the surface-blanket of dusty rubble contains a treasure trove of evidence of how the Moon formed.
12 JULY 2019
Recipe for Making H2O in the Lunar Regolith: Implant Solar Wind Hydrogen and Heat with Micrometeorite Impacts
by G. Jeffrey Taylor
Laboratory experiments simulating space weathering on the Moon show that water can be produced by rapid heating caused by micrometeorite impacts on grains implanted with hydrogen from the Sun.
24 MAY 2019
Active Asteroids
by Linda M. V. Martel
Researchers document the stunning effects of disintegrating asteroids to learn more about their dusty debris tails and the processes causing them to happen.
24 APRIL 2019
Volatile Elements Test Models for the Origin of the Moon
by G. Jeffrey Taylor
Volatile elements that concentrate in metallic iron elucidate the processes that operated during formation and initial differentiation of the Moon.
20 DEC 2018
The Complicated Origin of Earth's Water
by G. Jeffrey Taylor
Water delivery and redistribution to Earth was a complicated business with hydrogen coming from chondritic and solar nebular sources.
31 OCT 2018
Better Know A Meteorite Collection: Fersman Mineralogical Museum in Moscow, Russia
by Linda M. V. Martel
PSRD highlights places and people around the world who play central roles in caring for and analyzing meteorites.
21 SEPT 2018
Remembering Paul D. Spudis (1952-2018)
by G. Jeffrey Taylor
Paul was a geologist, visionary lunar scientist, and advocate for lunar exploration and humans returning to the Moon.
10 AUG 2018
The Oldest Volcanic Meteorite: A Silica-Rich Lava on a Geologically Complex Planetesimal
by G. Jeffrey Taylor
A volcanic meteorite is the oldest igneous meteorite identified so far, erupting onto its parent body only about 3 million years after the Solar System began to form.
18 JULY 2018
Minerals Track Chemical Reactions in Interstellar Space and in the Protoplanetary Disk
by G. Jeffrey Taylor
Mineral intergrowths in cosmic dust and primitive meteorites reveal processes that operated in interstellar space and in the protoplanetary disk surrounding the Sun before the planets formed.
14 JUNE 2018
Meteorite Evidence for a Complicated Protoplanetary Disk
by G. Jeffrey Taylor
A striking dichotomy in isotopic compositions of meteorite groups appears to be consistent with Jupiter and Saturn migrating to and fro during planet formation.
24 APRIL 2018
New Age for Lunar Exploration
by G. Jeffrey Taylor and Linda M. V. Martel
A change in the National Space Policy adds a lunar emphasis to NASA exploration programs.
20 NOV 2017
Volcanism and an Ancient Atmosphere on the Moon
by G. Jeffrey Taylor
Extensive lunar volcanism around 3.5 billion years ago produced a temporary atmosphere on the Moon.
9 OCT 2017
Accretional Layers Preserved in a Meteorite
by Linda M. V. Martel
Visible sequence of layers in the Isheyevo meteorite tells a story of impact debris deposited, layer by layer, onto the surface of the surviving planetesimal.
21 SEPT 2017
Remembering Lawrence A. Taylor (1938-2017) — A Taylor Perspective
by G. Jeffrey Taylor and S. Ross Taylor
Larry made significant contributions to lunar science, exploration, and resource utilization.
30 AUG 2017
Meteorite Formation Times and the Age of Jupiter
by G. Jeffrey Taylor
Isotopic analyses of meteorites and models of planetary accretion indicate that Jupiter's solid core had accreted only one million years after the Solar System began to form.
6 JUNE 2017
Archaeology, Artifacts, and Cosmochemistry
by Linda M. V. Martel
Iron beads, identified as pieces of the Anoka meteorite, are among a small handful of artifacts made from material from the birth of the Solar System.
4 MAY 2017
Two Billion Years of Magmatism in One Place on Mars
by G. Jeffrey Taylor
New data from a Martian meteorite extends the time of magmatic activity by 1.8 billion years in a volcanic center that provided us a coherent group of Martian meteorites.
17 APRIL 2017
Chondrules: Important, but Possibly Unfathomable
by G. Jeffrey Taylor
Studies of chondrules in meteorites have revealed much about them, except how they formed and if they played a role in forming planets.
11 NOV 2016
Searching for Ancient Solar System Materials on the Moon, Earth, and Mars
by G. Jeffrey Taylor
The early history of the Solar System is recorded by meteorites falling now, but also by those that fell hundreds of millions to billions of years ago, preserved in lunar samples, sedimentary layers on Earth, and even sitting on the surface of Mars.
30 AUG 2016
What Made the Doughnuts Inside Lunar Concentric Craters?
by David Trang
Concentric ridges inside small lunar craters may have formed when intrusion of magma caused uplift of the crater floor.
29 JUNE 2016
Rock and Roll at the Apollo 17 Site
by Linda M. V. Martel
The latest orbital images and topographic data offer new insights to the geologic context of Apollo 17 impact melt breccias.
2 JUNE 2016
A Sample from an Ancient Sea of Impact Melt
by G. Jeffrey Taylor
A lunar breccia from the Apollo 16 site contains a fragment formed in a sea of impact melt 4.2 billion years ago.
18 MAR 2016
Primordial Molecular Cloud Material in Metal-Rich Carbonaceous Chondrites
by G. Jeffrey Taylor
Dust from the molecular cloud that gave birth to the Sun may be preserved in objects formed in the outer reaches of the Solar System.
30 NOV 2015
Primeval Water in the Earth
by G. Jeffrey Taylor
Hydrogen isotopes in lavas derived from the deep mantle suggest the presence of a component inside the Earth that came directly from the primordial solar nebula.
30 OCT 2015
Age Rules
by G. Jeffrey Taylor
Rules for determining the most reliable ages for Moon rocks shed light on what rocks formed when during construction of the ancient lunar highlands crust.
31 JULY 2015
Making and Differentiating Planets
by G. Jeffrey Taylor
A detailed study forming Earth and differentiating it into core and mantle shows that it accreted heterogeneously and most water is added after 60% of the Earth had formed.
29 JUNE 2015
Chondritic Asteroids–When Did Aqueous Alteration Happen?
by Patricia M. Doyle
New dates determined for aqueous alteration on chondritic parent bodies, based on a new mineral standard, have big implications on the timing and location of accretion.
17 JUNE 2015
Tungsten Isotopes, Formation of the Moon, and Lopsided Addition to Earth and Moon
by G. Jeffrey Taylor
A distinct difference in tungsten isotopic composition between the Moon and Earth is consistent with the Moon and Earth starting with the same isotopic composition, but then modified by late accretion of different amounts of chondritic asteroids.
10 APRIL 2015
Ancient Jets of Fiery Rain
by G. Jeffrey Taylor
A new idea suggests that chondrules could have formed as the result of impact jetting caused when large planetesimals collided during planet formation.
28 JAN 2015
Water in Asteroid 4 Vesta
by G. Jeffrey Taylor
The big, melted asteroid 4 Vesta provides clues to the source of water to Earth and Mars.
23 DEC 2014
Moon's Pink Mineral
by Linda M. V. Martel and G. Jeffrey Taylor
Remote sensing detections of pink spinel anorthosite are compared with sample analyses and experimental results to learn more about the lunar crust.
23 JUNE 2014
The Importance of When
by G. Jeffrey Taylor
Isotopic analyses at the microscopic scale indicate an ancient age for an impact mixture from Mars and appear to confirm a young age for a group of basaltic lava flows.
17 JAN 2014
ICP-MS and Planetary Geosciences
by Jesse D. Davenport
ICP-MS techniques provide acurrate and rapid elemental analyses.
11 DEC 2013
The Igneous SPICEs Suite: Old Programs with a New Look
by Jesse D. Davenport
Long-established, reliable programs for calculating how magmas evolve have been given a facelift and used for modeling the crystallization of the lunar magma ocean.
16 SEPT 2013
Discovery of a New Garnet Mineral, Hutcheonite, in the Allende Meteorite
by Linda M. V. Martel
A new titanium-rich garnet mineral discovered in a CAI in Allende is named in honor of Dr. Ian D. Hutcheon.
30 MAY 2013
Magnesium-rich Basalts on Mercury
by Linda M. V. Martel
Crystallization modeling using the MELTS computer code with MESSENGER-derived compositions finds Mg-rich lavas on Mercury.
30 APRIL 2013
Meteoritic Minerals Tell a Story of Multistage Cooling, Break-up, and Reassembly of an Asteroid
by G. Jeffrey Taylor
Compositional variations in minerals in H-chondrites indicate at least two vastly different cooling rates at different temperatures, suggesting fragmentation, cooling of the fragments, and reassembly into a second-generation rubble pile.
20 FEB 2013
Remembering David S. McKay (1936-2013)
by G. Jeffrey Taylor
Over his distinguished and creative five-decade career Dave made significant contributions to planetary science.
30 JAN 2013
New Martian Meteorite is Similar to Typical Martian Crust
by G. Jeffrey Taylor
A newly-identified Martian meteorite from Northwest Africa is not like other Martian meteorites, but has a chemical composition similar to the average Martian crust.
10 DEC 2012
Zinc Isotopes Provide Clues to Volatile Loss During Moon Formation
by G. Jeffrey Taylor
Ratios of zinc isotopes indicate evaporation of zinc (and other volatiles) during formation of the Moon.
16 NOV 2012
Dating Transient Heating Events in the Solar Protoplanetary Disk
by G. Jeffrey Taylor
Startlingly precise dating of components in primitive meteorites indicate contemporaneous formation of calcium-aluminum-rich inclusions (CAIs) and chondrules.
26 OCT 2012
Exploring the Mantle of Mars
by G. Jeffrey Taylor and Linda M. V. Martel
Cosmochemistry and geophysics experts meet to discuss what we know and do not yet know about the composition, structure, and evolution of the Martian mantle.
31 JULY 2012
How Much Water is Inside Mars?
by G. Jeffrey Taylor
The interior of Mars appears to be as wet as the interior of Earth.
28 JUNE 2012
Leftovers from Ancient Lunar Impactors
by Linda M. V. Martel and G. Jeffrey Taylor
A systematic search for meteorite fragments in ancient regolith breccias confirms chondritic impactors on the Moon.
30 MAY 2012
Titanium Isotopes Provide Clues to Lunar Origin
by G. Jeffrey Taylor
The titanium isotopic mix is essentially identical in Earth and Moon, important new information with implications for the origin of the planets.
15 MAR 2012
Young Tectonic Events in Martian Chaotic Terrain
by Linda M. V. Martel
Study of a faulted landslide in Aureum Chaos and its ramifications.
21 FEB 2012
Chronicle of a Chondrule's Travels
by Linda M. V. Martel
Isotopic measurements of a chondrule in a Comet Wild 2 grain tell the story of outward migration of solar nebula solids, helping to set the formation age of Jupiter.
15 DEC 2011
Formation of Carbonate Minerals in Martian Meteorite ALH 84001 from Cool Water Near the Surface of Mars
by G. Jeffrey Taylor
A new approach to thermometry using isotopic compositions of carbon and oxygen indicates that carbonate minerals in Martian meteorite ALH 84001 formed at 18 ± 4 oC.
30 NOV 2011
Festival on the Formation of the First Solids in the Solar System
by G. Jeffrey Taylor and Linda M. V. Martel
Cosmochemists, astronomers, and astrophysical modelers shared data and ideas about the formation of the materials making up the Solar System.
27 OCT 2011
Remembering Ronald Greeley (1939-2011)
by Linda M. V. Martel
Ron, an exceptional mentor and researcher, focused on understanding planetary surface processes and geological histories.
21 SEPT 2011
Remembering Michael J. Drake (1946-2011)
by G. Jeffrey Taylor
Mike was a great researcher in cosmochemistry and planetary geology.
31 AUG 2011
Samples from Asteroid Itokawa
by G. Jeffrey Taylor and Linda M. V. Martel
Samples returned from asteroid Itokawa by the Hayabusa mission provide ground truth for astronomical observations and reveal that the little asteroid is eroding at a rate of tens of centimeters per million years.
8 AUG 2011
Crystallizing the Lunar Magma Ocean
by G. Jeffrey Taylor
Lab experiments help test ideas for the Moon's chemical composition and how its crust formed.
22 JUNE 2011
A Traveling CAI
by G. Jeffrey Taylor
Oxygen isotopes show that a calcium-aluminum-rich inclusion wandered throughout the inner Solar System before being incorporated into an asteroid.
27 MAY 2011
Timeline of Martian Volcanism
by Linda M. V. Martel
High-resolution images allow a larger range of crater sizes to date calderas and the last major periods of volcanic activity on Mars.
7 APRIL 2011
Wet, Carbonaceous Asteroids: Altering Minerals, Changing Amino Acids
by G. Jeffrey Taylor
Aqueous alteration in asteroids containing organic compounds leads to formation of hydrous minerals and changes in the mix of amino acids.
31 JAN 2011
Mineral Abundances in Martian Soils
by Linda M. V. Martel
Mineral abundances calculated from a trio of datasets reveal mixtures of unrelated igneous and alteration minerals in Martian dark soils.
30 NOV 2010
Supernova Confetti in Meteorites
by G. Jeffrey Taylor
Pre-solar grains carrying anomalous chromium-54 show evidence for formation in a supernova.
30 SEPT 2010
Unraveling the Origin of the Lunar Highlands Crust
by Linda M. V. Martel
Lunar meteorites contain clasts that may plausibly be samples of post-magma-ocean plutons that helped build the highlands crust.
25 AUG 2010
New View of Gas and Dust in the Solar Nebula
by G. Jeffrey Taylor
The current view holds that gas and dust in the solar nebula began with the same oxygen isotopic composition, then changed by processes in the nebula. A new view suggests that dust and gas had vastly different mixtures of oxygen isotopes in the first place.
1 JULY 2010
Damp Moon Rising
by G. Jeffrey Taylor
Cosmochemists find more evidence for water inside the Moon, showing that it is not the bone-dry place we thought.
10 JUNE 2010
Formation of Stony-Iron Meteorites in Early Giant Impacts
by Edward Scott, Joseph Goldstein, and Jijin Yang
Cosmochemical studies and dynamical models of hit-and-run planetary collisions suggest a new origin for the stony-iron meteorites called pallasites.
21 MAY 2010
A Younger Age for the Oldest Martian Meteorite
by G. Jeffrey Taylor
New isotopic analyses show that famous Martian meteorite ALH 84001 formed 4.09 billion years ago, not 4.50 billion years ago as originally reported.
30 APRIL 2010
Asteroid, Meteor, Meteorite
by Linda M. V. Martel
Detected in space less than a day before hitting Earth, the Almahata Sitta meteorite from asteroid 2008 TC3 gives clues to the complex evolution of small asteroids.
31 MAR 2010
Dynamics and Chemistry of Planet Construction
by G. Jeffrey Taylor
Planetary compositions allow us to test computer models of planet formation.
17 FEB 2010
How Young is the Lunar Crater Giordano Bruno?
by Linda M. V. Martel
High-resolution images are used to determine how recently this crater formed, a mere 832 years ago or over a million years ago.
21 JAN 2010
A Complication in Determining the Precise Age of the Solar System
by Gregory A. Brennecka
The presence of short-lived isotope Curium-247 in the early Solar System complicates the job of dating the earliest events in the solar nebula.
6 JAN 2010
Violent Adolescent Planet Caught Infrared Handed
by David Trang and Eric Gaidos
Infrared telescopic observations may have observed dust from an impact between protoplanets in the disk surrounding young star HD172555.
21 DEC 2009
Celebrated Moon Rocks
by Linda M. V. Martel
Overview and status of the Apollo lunar collection: A unique, but limited, resource of extraterrestrial material.
13 NOV 2009
An Even More Precise View of Aluminum-26 in the Solar Nebula
by G. Jeffrey Taylor
New, precise analyses of the short-lived isotope aluminum-26 indicate it was distributed uniformly throughout the early solar system, an important clue to its origin.
26 OCT 2009
Kaidun--A Meteorite with Everything but the Kitchen Sink
by Linda M. V. Martel
This unique breccia is called a single-stone meteorite collection.
18 SEPT 2009
The Growing Diversity of Lunar Basalts
by G. Jeffrey Taylor
A lunar basaltic meteorite adds complexity to the already complicated story of mare basalt volcanism on the Moon.
10 AUG 2009
Space Weathering Agent: Solar Wind
by Linda M. V. Martel
Bombardment of helium ions on olivine in the laboratory simulates space weathering of asteroids and other airless bodies.
6 JULY 2009
Better Know A Meteorite Collection: Natural History Museum in London, United Kingdom
by Linda M. V. Martel
PSRD highlights places and people around the world who play central roles in caring for and analyzing meteorites.
25 JUNE 2009
The Complicated Geologic History of Asteroid 4 Vesta
by G. Jeffrey Taylor
Meteorites from asteroid 4 Vesta show that it contains patches of granite-like rock.
11 MAY 2009
Better Know A Meteorite Collection: Natural History Museum in Vienna, Austria
by Linda M. V. Martel
PSRD highlights places and people around the world who play central roles in caring for and analyzing meteorites.
8 MAY 2009
Mars Crust: Made of Basalt
by G. Jeffrey Taylor
Chemical analyses of rocks on the Martian surface indicate that the Martian crust was built of basalt lava flows not much different from those on Earth.
25 MAR 2009
Time to Solidify an Ocean of Magma
by G. Jeffrey Taylor
A small mineral grain places limits on how long it took the lunar magma ocean to solidify.
19 FEB 2009
More Evidence for Multiple Meteorite Magmas
by G. Jeffrey Taylor
Cosmochemists show that a pair of meteorites formed in an asteroid that erupted a newly-recognized type of asteroidal magma.
27 JAN 2009
The Crazy Mixed-Up Lunar Crust
by Linda M. V. Martel
The horizontal and vertical distribution of well-mixed basin ejecta has lunar-wide geochemical ramifications.
14 DEC 2008
Wee Rocky Droplets in Comet Dust
by G. Jeffrey Taylor and Linda M. V. Martel
Tiny flash-melted objects in dust collected from comet Wild 2 were transported from the inner Solar System to the outer reaches where comets formed.
20 NOV 2008
Tiny Molten Droplets, Dusty Clouds, and Planet Formation
by G. Jeffrey Taylor
Roughly constant sodium concentration during chondrule crystallization suggests that these molten droplets formed in regions of the solar nebula that were enriched in rocky dust.
22 SEPT 2008
The Bone-Dry Moon Might be Damp
by G. Jeffrey Taylor
Cosmochemists have written in stone that the Moon is almost totally devoid of water, but new analyses of volcanic glasses suggest that they need to do some editing.
8 JULY 2008
Heating, Cooling, and Cratering: One Asteroid's Complicated Story
by G. Jeffrey Taylor
Cooling rate data indicate that the H-chondrite parent asteroid was deeply cratered as it cooled slowly.
30 MAY 2008
Meteorites Found on Mars
by Linda M. V. Martel
No surprise that there are meteorites on other planets. Now that we've seen them on Mars, what do we know about them and what does their geochemistry tell us about the environment where they landed?
29 APRIL 2008
A Farside Geochemical Window into the Moon
by Linda M. V. Martel
Findings show geochemical enhancements in the Dewar region are caused by thorium-rich mare basalt fragments in the regolith.
22 FEB 2008
Compositional Balancing Before Moon Formation
by G. Jeffrey Taylor
The identical oxygen isotopic composition of Earth and Moon might be explained by exchange of material between the proto-Earth and the surrounding proto-lunar disk.
8 FEB 2008
Remembering Gordon A. McKay (1945-2008)
by G. Jeffrey Taylor
Gordon was a great researcher who focused on experimental cosmochemistry.
19 DEC 2007
Chips Off an Old Lava Flow
by G. Jeffrey Taylor
Lunar meteorite Kalahari 009 contains fragments of basalt about 4.35 billion years old, a record-breaking old age for mare basalt.
27 NOV 2007
Getting to Know Vesta
by Linda M. V. Martel
Scientists are primed with geochemical data from HED meteorites for Dawn's encounter with asteroid 4 Vesta.
30 OCT 2007
Did an Impact Make the Mysterious Microscopic Magnetite Crystals in ALH 84001?
by G. Jeffrey Taylor
Tiny crystals of magnetite in Martian meteorite ALH 84001 might have been made when shock waves decomposed iron carbonate.
17 SEPT 2007
Melted Crumbs from Asteroid Vesta
by Linda M. V. Martel
Researchers studying some of the rarest of the smallest meteorites call them melted crumbs from asteroid Vesta.
6 JULY 2007
The Sun's Crowded Delivery Room
by G. Jeffrey Taylor
Isotopes in meteorites suggest that the Sun formed in a dense cluster of stars.
19 JUNE 2007
Oxidants from Pulverized Minerals
by Linda M. V. Martel
Laboratory measurements of hydrogen peroxide produced from crushed basaltic minerals immersed in water have important implications for Martian and lunar dust.
18 APRIL 2007
When Worlds Really Did Collide
by Edward Scott, Jijin Yang, and Joseph Goldstein
Cosmochemical studies and dynamical models of protoplanetary collisions suggest a new origin for iron meteorites.
3 APRIL 2007
Two Views of the Moon's Composition
by G. Jeffrey Taylor
There is a striking dichotomy in estimates of the abundance of refractory elements in the Moon.
29 JAN 2007
Did Martian Meteorites Come From These Sources?
by Linda M. V. Martel
Researchers find large rayed craters on Mars and consider the reasons why they may be launching sites of Martian meteorites.
25 JAN 2007
Organic Globules from the Cold Far Reaches of the Proto-Solar Disk
by G. Jeffrey Taylor
Hollow organic globules in the Tagish Lake meteorite probably formed far from the proto-Sun, maybe even in interstellar space before our Solar System formed.
19 DEC 2006
Squeezing Meteorites to Reveal the Martian Mantle
by G. Jeffrey Taylor
Experiments at high temperature and pressure give clues to the composition of the interior of Mars.
27 NOV 2006
Hit-and-Run as Planets Formed
by G. Jeffrey Taylor
Collisions between large protoplanets as the planets formed may have ripped some of them to shreds, producing molten asteroid-sized bodies, driving off water and other volatiles, and scrambling partially molten protoplanets.
8 NOV 2006
Recent Gas Escape from the Moon
by G. Jeffrey Taylor
Gases may have escaped from the Moon as recently as a million years ago, implying that the lunar interior is not as lethargic as conventional wisdom dictates.
26 OCT 2006
LIBS: Remote Analysis of Elemental Compositions
by Linda M. V. Martel
Laser-induced breakdown spectroscopy (LIBS) is an active remote sensing technique used for the rapid characterization of elemental compositions of materials.
24 AUG 2006
Wandering Gas Giants and Lunar Bombardment
by G. Jeffrey Taylor
Outward migration of Saturn might have triggered a dramatic increase in the bombardment rate on the Moon 3.9 billion years ago, an idea testable with lunar samples.
21 JULY 2006
Iron Meteorites as the Not-So-Distant Cousins of Earth
by William F. Bottke and Linda M. V. Martel
Numerical simulations suggest that some iron meteorites are fragments of the long lost precursor material that formed the Earth and other terrestrial planets.
14 JUNE 2006
Fossil Meteorite Unearthed From Crater
by Linda M. V. Martel
A meteorite of unusual chondritic composition was found in a highly unlikely place, challenging how we think about colossal impact events on Earth.
26 MAY 2006
Interstellar Organic Matter in Meteorites
by G. Jeffrey Taylor
Carbonaceous chondrites contain organic compounds with high deuterium/hydrogen ratios, suggesting they formed in interstellar space.
30 APRIL 2006
Finding Basalt Chips from Distant Maria
by G. Jeffrey Taylor
Tossed chips of lava help fill in blanks in our knowledge of lunar basalts.
31 MAR 2006
A Primordial and Complicated Ocean of Magma on Mars
by G. Jeffrey Taylor
Geophysical and geochemical calculations indicate that total melting of Mars during its formation could have led to large-scale heterogeneities in its mantle.
28 FEB 2006
Ion Microprobe
by Linda M. V. Martel and G. Jeffrey Taylor
Instrument of Cosmochemistry
31 JAN 2006
Cosmochemistry from Nanometers to Light-Years
by G. Jeffrey Taylor
Cosmochemists and astronomers test theories on the formation of stars and planets.
27 DEC 2005
Magma and Water on Mars
by G. Jeffrey Taylor
Martian meteorites tell us part of the fascinating story about when volcanoes erupted and water flowed.
22 NOV 2005
Gamma Rays, Meteorites, Lunar Samples, and the Composition of the Moon
by G. Jeffrey Taylor
Lunar meteorites provide ground truth to help calibrate orbital geochemical data, allowing an estimate of the composition of the entire Moon.
21 OCT 2005
Little Chondrules and Giant Impacts
by G. Jeffrey Taylor
Chondrules in metal-rich meteorites formed a couple of million years after most other chondrules, possibly by impact between moon-sized or larger objects.
30 SEPT 2005
Portales Valley: Not Just Another Ordinary Chondrite
by Alex Ruzicka and Melinda Hutson
A melted meteorite gives a snapshot of the heat and shock that wracked an asteroid during the first stages of differentiation.
29 JULY 2005
Martian Meteorites Record Surface Temperatures on Mars
by G. Jeffrey Taylor
Gases trapped in Martian meteorites indicate that Mars has been a cold desert for a long, long time.
7 JULY 2005
Squeezing and Heating Rock to Scope Out How Metallic Iron Dribbled to the Center of the Earth
by G. Jeffrey Taylor
Experiments showing how cobalt and nickel concentrate in molten metal shed light on the formation of Earth's metallic core.
31 MAY 2005
Making Sense of Droplets Inside Droplets
by G. Jeffrey Taylor
The vexing presence of chondrules inside supposedly older calcium-aluminum-rich inclusions (CAIs) in chondrites makes sense if the CAIs were remelted.
13 APRIL 2005
Antarctic Guide to Martian Weathering
by Linda M. V. Martel
Soils in the Antarctic Dry Valleys contain traces of silicate alteration products and secondary salts much like those found in Martian meteorites.
31 JAN 2005
Recent Activity on Mars: Fire and Ice
by Linda M. V. Martel
New images from Mars Express show evidence of recent volcanic and glacial activity on Mars, consistent with what we know from Martian meteorites and previous evaluations of the planet's internal heat production and climate.
23 DEC 2004
Cosmochemistry and Human Exploration
by G. Jeffrey Taylor
Cosmochemistry plays an important role in developing local resources on the Moon and Mars, essential to sustained human presence in space.
10 DEC 2004
Composition of the Moon's Crust
by Linda M. V. Martel
New empirical calibrations of Lunar Prospector and Clementine data yield improved global maps of Th, K, and FeO.
31 OCT 2004
New Lunar Meteorite Provides its Lunar Address and Some Clues about Early Bombardment of the Moon
by G. Jeffrey Taylor
A newly discovered meteorite from the Moon provides a detailed record of its history, allowing scientists to make a reasonable guess about where it came from on the Moon and to test ideas for the timing of early impact bombardment.
28 SEPT 2004
Lunar Crater Rays Point to a New Lunar Time Scale
by Linda M. V. Martel
Optical maturity maps of rays, derived from Clementine multispectral data and calibrated with lunar sample analyses, provide a new way to define the two youngest time stratigraphic units on the Moon.
26 AUG 2004
Meteorite Shower in Park Forest, Illinois
by Linda M. V. Martel
An L5 chondrite strewnfield is centered at Park Forest, Illinois, a southern suburb of Chicago.
5 JULY 2004
New Mineral Proves an Old Idea about Space Weathering
by Linda M. V. Martel
A newly discovered vapor-deposited iron silicide in a lunar meteorite has been named hapkeite.
1 JULY 2004
Carbonates in ALH 84001: Part of the Story of Water on Mars
by Catherine M. Corrigan
The study of multi-generational carbonate assemblages in Martian meteorite ALH 84001 reveals a complex history of crystal formation, growth, and alteration.
23 JUNE 2004
The Multifarious Martian Mantle
by G. Jeffrey Taylor
Detailed analyses of Martian meteorites reveal that the planet's interior preserves distinctive regions that formed 4.5 billion years ago.
1 JUNE 2004
Silicate Stardust in Meteorites
by G. Jeffrey Taylor
Silicates are the most abundant solids in disks around growing stars, but presolar silicates have not been found in even the most primitive meteorite--until now.
21 APRIL 2004
The Oldest Moon Rocks
by Marc Norman
Rocks from the lunar crust provide new clues to the age and origin of the Moon and the terrestrial planets.
2 APRIL 2004
Asteroid Heating: A Shocking View
by G. Jeffrey Taylor
Mineral intergrowths in chondritic meteorites may indicate that some asteroids were heated by impact.
9 MAR 2004
Tiny Traces of a Big Asteroid Breakup
by Linda M. V. Martel
Fossil meteorites and chromite grains record a hundred-fold increase in the number of meteorites that fell 480 million years ago compared to the meteorite influx today.
28 NOV 2003
Hafnium, Tungsten, and the Differentiation of the Moon and Mars
by G. Jeffrey Taylor
Experiments help us understand the timing of core formation and nature of initial melting in the Moon and Mars.
7 NOV 2003
Pretty Green Mineral -- Pretty Dry Mars?
by Linda M. V. Martel
The discovery of olivine-bearing rocks on Mars underscores the need to understand weathering rates of silicates in the Martian environment.
28 OCT 2003
Show Me the Carbonates
by Linda M. V. Martel
Carbonate minerals intermingle with silicates in the Martian surface dust.
29 AUG 2003
A New Type of Stardust
by G. Jeffrey Taylor
Interplanetary dust particles contain rare grains that formed in stars older than the Sun.
29 AUG 2003
Gullied Slopes on Mars
by Linda M. V. Martel
Do the Martian gullies tell us something about the stability and distribution of near-surface water?
16 JULY 2003
Ancient Floodwaters and Seas on Mars
by Linda M. V. Martel
Surface deposits within the northern lowlands support the oceans hypothesis.
4 JUNE 2003
The Moon's Dark, Icy Poles
by Linda M. V. Martel
Permanently shadowed regions on the Moon--where frozen water could be trapped--are more abundant and more widely distributed than originally thought.
21 MAY 2003
Triggering the Formation of the Solar System
by G. Jeffrey Taylor
New data from meteorites indicates that formation of the Solar System was triggered by a supernova.
28 APRIL 2003
Asteroidal Lava Flows
by G. Jeffrey Taylor
Meteorite studies indicate that we have pieces of lava flows from at least five asteroids.
13 MAR 2003
Gray Iron Oxide in Meridiani, Mars
by Linda M. V. Martel
A deposit of gray hematite in Terra Meridiani may suggest that water once circulated through the rock layers in this region of Mars.
23 JAN 2003
QUE 93148: A Part of the Mantle of Asteroid 4 Vesta?
by Christine Floss
A tiny meteorite tells a story of melting in the deep mantle of a big asteroid.
12 DEC 2002
Tagish Lake -- A Meteorite from the Far Reaches of the Asteroid Belt
by David W. Mittlefehldt
A new type of primitive meteorite with much to tell us about the formation of the solar system.
25 NOV 2002
Bands on Europa
by Linda M. V. Martel
Rifting at Earth's mid-ocean ridges is a good analogy for Europan band formation.
24 OCT 2002
The First Rock in the Solar System
by Steven B. Simon
An aggregate of corundum, hibonite, and perovskite may be among the first rocks to form in the Solar System.
8 OCT 2002
The Moon Beyond 2002
by G. Jeffrey Taylor
A meeting of lunar scientists to outline research questions and future exploration plans.
30 SEPT 2002
Using Aluminum-26 as a Clock for Early Solar System Events
by Ernst Zinner
Correspondence between 26Al and Pb-Pb ages shows that 26Al records a detailed record of events in the early solar system.
25 SEPT 2002
Dating the Earliest Solids in our Solar System
by Alexander N. Krot
Lead isotopic analyses give absolute formation ages of Ca-Al-rich inclusions and chondrules.
30 AUG 2002
The Wet, Oxidizing Crust of Mars
by G. Jeffrey Taylor
Analysis of isotopes and oxide minerals in Martian meteorites indicate that many magmas interacted with a wet, oxidizing crust as they oozed from the Martian mantle to its reddish surface.
28 JUNE 2002
Using Chondrites to Understand the Inside of Asteroid 433 Eros
by Linda M. V. Martel
Data from ordinary chondrite meteorites and from the NEAR mission suggest that asteroid 433 Eros is heavily fractured.
5 JUNE 2002
Dirty Ice on Mars
by G. Jeffrey Taylor
Instruments on the Odyssey spacecraft show that a lot of dirty ice sits within a meter of the surface in the south polar latitudes of Mars.
22 MAY 2002
The Tricky Business of Identifying Rocks on Mars
by G. Jeffrey Taylor
A new analysis of thermal emission spectra suggests a new interpretation for the composition of the Martian surface.
13 MAY 2002
Resolution of a Big Argument About Tiny Magnetic Minerals in Martian Meteorite
by Edward R. D. Scott and David J. Barber
Magnetic minerals in Martian meteorite ALH 84001 formed as a result of impact heating and decomposition of carbonate. They were never used as compasses by Martian microorganisms.
28 FEB 2002
Searching Antarctic Ice for Meteorites
by Linda M. V. Martel
Silver anniversary season: The vigorous life and times of the ANSMET team at Meteorite Hills resulted in a new set of 336 meteorites collected off the ice.
26 FEB 2002
The Composition of Asteroid 433 Eros
by G. Jeffrey Taylor
X-rays and reflected light suggest that asteroid 433 Eros is similar in composition to the most common type of meteorite--maybe.
3 DEC 2001
Oxygen Isotopes Give Clues to the Formation of Planets, Moons, and Asteroids
by Edward R. D. Scott
As they formed from gas and dust near the Sun, grains in some meteorites acquired oxygen that originated in numerous other stars that shone long before our solar system was born.
7 NOV 2001
Meteorites on Ice
by Linda M. V. Martel
Antarctic meteorites provide a continuous and readily available supply of extraterrestrial materials, stimulating new research and ideas in cosmochemistry, planetary geology, astronomy, and astrobiology.
22 OCT 2001
New Data, New Ideas, and Lively Debate about Mercury
by G. Jeffrey Taylor
A hundred scientists gathered to share new data and ideas about the important little planet closest to the Sun.
21 AUG 2001
Uranus, Neptune, and the Mountains of the Moon
by G. Jeffrey Taylor
The tardy formation of Uranus and Neptune might have caused the intense bombardment of the Moon 3.9 billion years ago.
26 JUNE 2001
If Lava Mingled with Ground Ice on Mars
by Linda M. V. Martel
Planetary geologists use Icelandic volcanic formations called "rootless cones" to explain clusters of small cones on Mars.
14 JUNE 2001
Outflow Channels May Make a Case for a Bygone Ocean on Mars
by Linda M. V. Martel
Mars Orbiter Laser Altimeter data have given scientists a new perspective of the dry channels in Chryse Planitia and a new approach to testing the Martian ancient ocean hypothesis.
24 APRIL 2001
Gullies and Canyons, Rocks and Experiments: The Mystery of Water on Mars
by G. Jeffrey Taylor
The combination of analyses of Martian meteorites and laboratory experiments helps scientists understand how water in magma has changed the Martian crust and surface.
2 MAR 2001
Relicts from the Birth of the Solar System
by G. Jeffrey Taylor
Rapidly cooled silicate droplets found in unusual meteorites may have formed directly from the cloud of gas and dust surrounding the young Sun.
28 FEB 2001
Buckyballs and Gases May Mark Massive Extinction
by G. Jeffrey Taylor
Helium and argon isotopes in fullerenes suggest an impact triggered the incredible extinction that marks the end of the Permian period.
26 FEB 2001
The Europa Scene in the Voyager-Galileo Era
by Linda M. V. Martel
Voyager and Galileo images provide a 20-year perspective on the geology of Europa's water-ice surface.
24 JAN 2001
Lunar Meteorites and the Lunar Cataclysm
by Barbara A. Cohen
Dating of impact melts in lunar meteorites supports the idea that the Moon was intensely bombarded about 3.9 billion years ago.
5 DEC 2000
Recipe for High-Titanium Lunar Magmas
by G. Jeffrey Taylor
Experiments shed light on how high-titanium lunar magmas formed.
21 NOV 2000
Mining the Moon, Mars, and Asteroids
by G. Jeffrey Taylor
Applied cosmochemistry plays a key role in plans to use the resources of the Moon, Mars, and asteroids.
30 SEPT 2000
The Oldest Metal in the Solar System
by G. Jeffrey Taylor
Grains of metallic iron in some chondritic meteorites condensed from hot clouds of gas and dust while the Sun was forming.
31 AUG 2000
A New Moon for the Twenty-First Century
by G. Jeffrey Taylor
Integrated studies of returned samples and remote sensing data reveal a Moon far different from the one scientists envisaged only a decade ago.
23 JUNE 2000
The Surprising Lunar Maria
by G. Jeffrey Taylor
Global remote sensing data have given lunar scientists a startling new perspective of the titanium concentrations in the lava flows making up the lunar maria.
24 MAY 2000
Liquid Water on Mars: The Story from Meteorites
by G. Jeffrey Taylor
Martian meteorites may have reacted with liquid water on Mars intermittently during the past 650 million years.
26 APRIL 2000
Analyzing Next to Nothing
by G. Jeffrey Taylor
Cosmochemists can analyze astonishingly small particles, skills essential to the analysis of samples to be returned from comets, asteroids, Martian moons, and Mars.
28 MAR 2000
Supernova Debris in the Solar System
by G. Jeffrey Taylor
Calculations suggest that a supernova explosion would distribute its debris uniformly throughout the cloud of gas and dust from which the Solar System formed.
10 MAR 2000
Flash Heating
by G. Jeffrey Taylor
Extremely rapid heating of rocky materials in a furnace is possible, making it feasible to study the formation of melted droplets in meteorites.
15 FEB 2000
Jupiter's Hot, Mushy Moon
by G. Jeffrey Taylor
Very high lava flow temperatures on Io lead some scientists to propose that the satellite's interior is a swirling cauldron of partially molten rock.
17 DEC 1999
Difficult Experiments on Weird Rocks
by G. Jeffrey Taylor
Melting experiments on oxygen-depleted meteorites give clues about magma compositions and core formation in asteroids.
17 DEC 1999
Zapping Mars Rocks with Gamma Rays
by G. Jeffrey Taylor
One way to sterilize samples from Mars is to zap them with gamma rays. Will this ruin the rock for other studies? Apparently not.
24 NOV 1999
Purple Salt and Tiny Drops of Water in Meteorites
by G. Jeffrey Taylor
Two meteorites contain crystals of sodium chloride that have trapped tiny drops of ancient salty water.
23 SEPT 1999
The Moon at its Core
by Linda M. V. Martel
New evidence for a small lunar core strengthens the giant impact hypothesis for the origin of the Moon.
24 AUG 1999
Honeycombed Asteroids
by G. Jeffrey Taylor
Asteroids have lower densities than expected, probably because they have been disrupted and then reassembled into porous rubble piles.
30 JULY 1999
Fossils Blowing in the Wind: More Contamination of Antarctic Meteorites
by G. Jeffrey Taylor
Terrestrial microfossils occur in cracks in Antarctic meteorites, making it difficult to search for extraterrestrial life in meteorites.
20 JULY 1999
An Adulterated Martian Meteorite
by G. Jeffrey Taylor
Martian meteorite EETA79001 may have formed by impact melting and mixing of other Martian rocks, not by simple igneous activity as originally thought.
3 JUNE 1999
Martian Organic Matter in ALH84001?
by G. Jeffrey Taylor
Indigenous organic compounds in ALH84001 may be from meteorite bombardment of the surface of Mars.
21 APRIL 1999
30th Lunar and Planetary Science Conference: Some Highlights
by G. Jeffrey Taylor
The annual LPSC featured bacteria, new views of the Moon, and an intriguing new meteorite.
8 FEB 1999
From a Cloud of Gas and Dust to an Asteroid with Percolating Hot Water
by G. Jeffrey Taylor
Isotopes of manganese and chromium indicate that chemical reactions involving hot water altered minerals on water-bearing asteroids during the same time interval that other asteroids were melted, between 7 and 16 million years after the first solids formed in the Solar System.
31 DEC 1998
Origin of the Earth and Moon
by G. Jeffrey Taylor
First hand report of the December 1998 conference on the formation and very early history of the Earth and Moon.
12 NOV 1998
Dry Droplets of Fiery Rain
by G. Jeffrey Taylor
Experiments test an idea for the origin of droplets of rocky material melted before the planets formed.
24 SEPT 1998
Europa's Salty Surface
by G. Jeffrey Taylor
Jupiter's moon Europa has salt deposits on its surface that may be the products of evaporation of water erupted from an ocean beneath the satellite's icy crust.
24 SEPT 1998
For a Cup of Water on Mars: Gusev Crater
by Linda M. V. Martel
Gusev crater's long history as a depositional site for water-laid sediments makes it a priority site for future biological explorations.
17 JULY 1998
The Biggest Hole in the Solar System
by G. Jeffrey Taylor
Recent missions have helped researchers determine the composition of one of the largest impact craters in the Solar System: South Pole-Aitken basin.
27 APR 1998
Big Mountain, Big Landslide on Jupiter's Moon, Io
by Linda M. V. Martel
Thrust faulting and uplift of a large block of Io's crust may have created a mountain and the landslide on it.
17 FEB 1998
Organic Compounds in Martian Meteorites May Be Terrestrial Contaminants
by A. J. T. Jull
Carbon-14 measurements indicate that most of the organic compounds in martian meteorite ALH84001 were acquired on Earth, not Mars, weakening the case for fossil martian life in the meteorite.
18 DEC 1997
Fossils in Martian Meteorite: Real or Imagined?
by G. Jeffrey Taylor
Some scientists suggest that the small, wormy structures in martian meteorite ALH84001 are features of the crystals in the rock, decorated with artifacts introduced during sample preparation, not nanofossils. The discoverers of the fossil-like objects disagree.
11 DEC 1997
Damage by Impact: the case at Meteor Crater, Arizona
by Linda M. V. Martel
A look at the pre- and post-impact environments at Meteor Crater, Arizona provides insight into Earth's impact history. Just how often does this sort of impact event occur on Earth? We'll examine the potential hazards.
20 OCT 1997
Moonbeams and Elements
by G. Jeffrey Taylor
The amount of light reflected off the Moon can be used to determine elemental abundances from orbit.
22 AUG 1997
The Martian Interior
by G. Jeffrey Taylor
Data from martian meteorites and high pressure experiments give us a glimpse of the interior of the planet Mars.
22 AUG 1997
Testing the Evidence for Life on Mars: NASA and NSF Fund New Studies of Martian Meteorite
by G. Jeffrey Taylor
Newly awarded grants will fund 23 projects to further analyze martian meteorite ALH84001 and the details that led to last year's announcement of possible ancient martian life.
8 JULY 1997
Moving Stars and Shifting Sands of Presolar History
by Donald D. Clayton
Meteorites contain tiny grains of minerals cast off from ancient stars before the birth of our own Solar System. These grains tell a story of element formation, motions inside stars, and migration of stars in the Galaxy.
22 MAY 1997
Shocked Carbonates may Spell N-o L-i-f-e in Martian Meteorite ALH84001
by Edward R. D. Scott
Evidence for redistribution of carbonates by shock casts doubt on fossil life in martian meteorite.
22 MAY 1997
Low-temperature Origin of Carbonates Consistent with Life in ALH84001
by G. Jeffrey Taylor
Evidence from magnetism and isotopes consistent with life in martian meteorite.
31 MAR 1997
Life on Mars--The Debate Continues
by G. Jeffrey Taylor
Scientists continue their search for answers to the question of fossil life in a martian meteorite. Have we found evidence for life, nonbiologic processes or contamination? The great debate is far from over.
31 MAR 1997
Not Quite a Meeting of the Minds
by G. Jeffrey Taylor
The debate about life in martian meteorite ALH 84001 at the 28th Lunar and Planetary Science Conference was vigorous. Some investigators will turn out to be right, others wrong, but there will be no losers.
14 FEB 1997
1997 Apparition of Comet Hale-Bopp
by Karen J. Meech
With its closest approach to Earth on March 22, 1997, comet Hale-Bopp gave a spectacular night time show. This article also covers the historical development of cometary science and the scientific importance of comets.
12 FEB 1997
Explosive Volcanic Eruptions on the Moon
by Catherine M. Weitz
How did deposits of fine-grained volcanic beads form on the Moon? Could these deposits supply oxygen and rocket fuel to future lunar colonists?
23 JAN 1997
Mercury Unveiled
by G. Jeffrey Taylor
New analysis of 1970's data returned by the Mariner 10 mission reveals the nature of the surface of Mercury.
21 DEC 1996
Ice on the Bone Dry Moon
by Paul D. Spudis
Deposits of ice in the permanently dark regions near the south pole of the Moon could bootstrap a self-sustaining lunar colony.
21 DEC 1996
Meteorites from Mars, Rocks from Canada
by Rachel C. Friedman
There is more to Mars rocks than suspected fossils. Scientists are using ancient lava flows in eastern Ontario to understand the formation of a group of meteorites from Mars.
21 DEC 1996
Life Underground
by G. Jeffrey Taylor
Some bacteria live on nothing but rock and water, extracting energy from chemical reactions rather than from sunlight.
18 OCT 1996
Life on Mars?
by G. Jeffrey Taylor
A group of scientists, headed by Dr. David McKay of Johnson Space Center, have made a case for ancient life on Mars based on features in a meteorite found in Antarctica. Do we indeed have evidence of life on Mars?
18 OCT 1996
Rules for Identifying Ancient Life
by G. Jeffrey Taylor
Scientists seeking the oldest fossils on Earth have developed rules for establishing that they have found fossils and that the fossils formed in place.