Source of KT asteroid

[Richard Cowen <cowen@blueoakfarm.com>]

From the week of September 7, 2007. The source of the K-T asteroid.

The paper is in Nature, so it won't be generally available on the  
Web. It is a terrific paper. Assuming the orbital mechanics and  
computer programs are done properly, the authors identify the KT  
asteroid as most likely a member of a family of asteroids formed in  
the Jurassic as a result of a major collision in the asteroid belt,  
that were then spread out into the inner Solar System over the next  
100 million years. The crater Tycho on the Moon may have been formed  
by another member. As Claeys and Tagle mention in a commentary (also  
in Nature), it is spine-chilling to think that the dinosaurs were  
doomed before most of them had even evolved! There will be discussion  
and LOTS of empty speculation, but unless the foundations of this  
paper are flawed seriously, it will become a classic. Instructors in  
History of Life courses should make sure they understand the outline  
of the story: it's accessible to and should be fascinating for  
undergraduates.

http://news.nationalgeographic.com/news/2007/09/070905-asteroid- 
crash.html
National Geographic News

http://www.terradaily.com/reports/ 
Large_Asteroid_Breakup_Likely_Source_Of_Mass_Extinction_Impact_65_Millio 
n_Years_Ago_999.html

Terra Daily site

http://news.bbc.co.uk/2/hi/science/nature/6980468.stm
BBC News

http://www.sciencenews.org/articles/20070908/fob3.asp
Article by Ron Cowen (no relation) in Science News

http://www.swri.org/press/2007/asteroid.htm
Useful images


Hope this helps.
Cheers

Richard