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Thanks decimon.

Scientists Find Signs of Meteor Crash That Led to Extinctions in Era Before Dinosaurs
by Kenneth Chang
February 23, 2001
Dr. Becker, Dr. Poreda and their colleagues had previously found buckyballs at an impact crater in Sudbury, Canada, and in two meteorites. They have also found buckyballs containing similar types of gases in sediments dating from the dinosaur extinctions.

In the experiments, the scientists extracted buckyballs -- not just the typical sphere consisting of 60 carbon atoms, but also larger versions with up to 160 atoms -- from the sediments with organic solvents.

They then opened the buckyballs to release the helium and argon inside them. The nuclei of most helium atoms consist of two protons and two neutrons. A few -- one out of 700,000 helium atoms in the atmosphere -- are a lighter version, with only one neutron. For the helium in the buckyballs, a much larger fraction -- one out of 5,000 -- was the lighter version, similar to the ratio produced by fusion in stars.

The argon indicated a similar story, with low concentrations of a version that is commonly produced on Earth from the radioactive decay of potassium.

"I think the argon isotope ratio measurement is very convincing," said Dr. Kenneth A. Farley, a professor of geochemistry at the California Institute of Technology. "That's very hard to understand if it's not extraterrestrial."

Global warming my a-.



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New Extinction Clues Point to Deep Impact
by Paul Recer
May 10, 2001
New evidence shows that an extinction event in which more than half of all Earth species died 200 million years ago happened quickly, possibly as a result of an impact from outer space. The extinction, at the boundary of the Triassic and Jurassic periods of geologic history, is similar in its suddenness to two extinction events that have been linked to space rocks' impacts on the Earth. Researchers analyzing deposits from a rock formation on a remote beach front in Canada found evidence of a sharp shift in organic carbon levels at precisely the point in time that the Triassic-Jurassic extinction occurred. This is the first time scientists have found a clear carbon signature for what is called the TJ event, said Peter D. Ward, a researcher at the University of Washington... Similar evidence has been found for the Cretaceous-Tertiary extinction event 65 million years ago that killed off the dinosaurs, and for the much earlier Permian extinction 250 million years ago that killed 90 percent of all species... If the researchers find evidence that a space rock impact caused the TJ extinction, it will mean that three of the five major extinctions in the 4.5-billion-year history of the Earth are linked to the impact of asteroids or comets... Ward said that no impact crater on Earth has been shown to have a proven link to the TJ extinction event, although the Manicougan Crater in Quebec is considered a candidate. That crater was caused by a space impact, but it has been dated at 214 million years, well before the TJ event.