More Comet Stuff

[uniface]

In the April Geology, researchers describe finding chemical similarities in the cores between a layer corresponding to 1908, when a 50,000-metric-ton extraterrestrial object exploded over Tunguska, Siberia, and a deeper stratum dating to 12,900 years ago. They argue that the similarity is evidence that an object weighing as much as 50 billion metric tons triggered the Younger Dryas, a millennium-long cold spell that began just as the ice age was loosing its grip (SN: 6/2/07, p. 339).

Precipitation that fell on Greenland during the winter after Tunguska contains a strong, sharp spike in ammonium ions that can’t be explained by other sources such as wildfires sparked by the fiery explosion, says study coauthor Adrian Melott, a physicist of the University of Kansas in Lawrence.

“There’s a remarkable peak of ammonium ions in ice cores from Greenland at the beginning of the Younger Dryas,” comments Paul Mayewski, a glaciologist at the University of Maine in Orono who was not involved in the new study. The new findings are “a compelling argument that a major extraterrestrial impact occurred then,” he notes.


New Evidence of Ice Age Comet Found in Ice Cores | Wired Science | Wired.com

[eddies]

very cool,thanks for posting

[ghost recon]

Good stuff, interesting thread. Here's a couple of on topic links.

Nano-diamonds support comet theory of mass extinction: Study

YouTube - Clovis Comet & North American Mass Extinction

Clovis comet was said to be 100 times bigger than the Russian event in Tunguska, it's said to have been three miles wide. Makes me wonder when the next rock is due?