Sunday, December 06, 2009
Did comet broil the dinosaurs?
UA planetary scientists Tamara Goldin and Jay Melosh have an article published in the latest issue of GSA's Geology that models ejecta re-entering the atmosphere from the Chicxulub impact that may have killed the dinosaurs at the end of the Cretaceous.
They conclude that the heat from the ejecta being heated up again was about equal to that of an oven set to broil for several minutes according to a summary at Physorg.com.
Tamara and Jay were examining the idea that the ejecta would have been hot enough to start wildfires and wipe out animals worldwide.
Instead, the model indicates the pulse may not have ignited the forests but was hot enough to kill lots of plants and animals.
Ref: Self-shielding of thermal radiation by Chicxulub impact ejecta: Firestorm or fizzle?Tamara J. Goldin and H. Jay Melosh, Lunar and Planetary Lab, University of Arizona, Tucson, Arizona 85721, USA. Pages 1135-1138.
at 6:24 PM