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EGS-AGU-EUG Joint Assembly, Nice, April 2003 Mass-extinction controversy flares again Core from asteroid crater fuels debate on what wiped out the dinosaurs. 10 April 2003 REX DALTON [photo] The dinosaurs were wiped out 65 million years ago. © alamy.com A claim that the asteroid that struck Mexico 65 million years ago did not cause the mass extinction that wiped out dinosaurs triggered heated debate at a meeting this week. The announcement is based on preliminary analysis of the first core drilled into the 185-kilometre Chicxulub asteroid crater near the Yucatan Peninsula. Gerta Keller of Princeton University in New Jersey says...

Maine Crater Related to Dino-Killer Asteroid? By Larry O'Hanlon, Discovery News April 3, 2003 — The evidence is still skimpy, but there is a chance that the dino killer asteroid was not alone when it walloped the Earth 65 million years ago. A possible second crater, at least as big or bigger than the famous Chicxulub crater off Mexico's Yucatan peninsula, may have been created by a second hit moments after Chicxulub and off the coast of Maine. "It probably is a crater, but we really don't have age data," said marine geologist Dallas Abbott Lamont-Doherty Earth Observatory at Columbia...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 March 1 Stereo Eros Credit: NEAR Project, JHU APL, NASA Explanation: Get out your red/blue glasses and float next to asteroid 433 Eros, 170 million kilometers away! Orbiting the Sun once every 1.8 earth-years, asteroid Eros is a diminutive 40 x 14 x 14 kilometer world of undulating horizons, craters, boulders and valleys. Its unsettling scale and bizarre shape are emphasized in this picture - a mosaic...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 February 16 Southwest Mercury Credit: Mariner 10, NASA Explanation: The planet Mercury resembles a moon. Mercury's old surface is heavily cratered like many moons. Mercury is larger than most moons but smaller than Jupiter's moon Ganymede and Saturn's moon Titan. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron. In fact, the Earth is the only planet more...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 November 30 Surveyor Hops Credit : Surveyor Project, NASA Explanation: This panorama of the cratered lunar surface was constructed from images returned by the US Surveyor 6 lander. Surveyor 6 was not the first spacecraft to accomplish a soft landing on the Moon ... but it was the first to land and then lift off again! After the spacecraft touched down near the center of the Moon's...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 August 8 Ancient Volcanos of Mars Credit: Malin Space Science Systems, MOC, MGS, JPL, NASA Explanation: Findings of ancient martian microbial fossils in meteorites and liquid water related features on Mars' surface are currently controversial issues. But one thing long established by space-based observations of the Red Planet is the presence of volcanos, as Mars supports some of the largest volcanos in the solar system. This synthetic...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 July 16 Outbound from Mercury Credit: Mariner 10, NASA Explanation: After just passing Mercury, the robot spacecraft Mariner 10 looked back. The above picture is what it saw. Mercury, the closest planet to the Sun, is heavily cratered much like Earth's Moon. As Mercury slowly rotates, its surface temperature varies from an unbearably cold -180 degrees Celsius in the half facing away from the Sun, to an...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 June 27 Carving Ma'adim Vallis Credit: R. Irwin III (CEPS/NASM,UVa), T. Maxwell, A. Howard, R. Craddock, D. Leverington Explanation: Just as erosion from the Colorado River carved the Grand Canyon on Earth, a river of flood water may have carved Ma'adim Vallis, one of the largest canyons on Mars. Researchers have presented strong evidence for such a scenario based on elevation data recorded by the MOLA (Mars...

What Caused Argentina's Mystery Craters? By Ben Harder for National Geographic News May 9, 2002 For more than a decade, planetary scientists have been puzzling over a mixed bag of meteorite evidence scarring Argentina's plains. They gradually pieced together clues to reconstruct what seemed to be a rough-hewn but generally accurate account of a prehistoric meteorite impact. A mere 10,000 years ago, scientists deduced in the original theory, a sizable meteorite came hurtling through the atmosphere at a bizarrely low angle, smacked the ground with a glancing blow, and broke into numerous pieces that gouged separate, miles-long scars in the...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 March 22 Odyssey Over Mars Credit: THEMIS, Mars Odyssey Team, JPL, NASA Explanation: Scroll right and journey for 300 kilometers over Terra Sirenum in the cratered highlands of southern Mars. The infrared view, 32 kilometers wide, was recently recorded by the THEMIS camera on board the orbiting Mars Odyssey spacecraft. Beginning at the north (left) edge, the scene sweeps across the floor and over the rim of...