Supernova debris found on Earth
Mark Peplow
Ancient explosion may have affected climate and, possibly, human evolution.

Cosmic fallout from an exploding star dusted the Earth about 2.8 million
years ago, and may have triggered a change in climate that affected the
course of human evolution. The evidence comes from an unusual form of iron
that was blasted through space by a supernova before eventually settling
into the rocky crust beneath the Pacific Ocean.

Gunther Korschinek, a physicist from the Technical University of Munich in
Germany, leads a team who in 1999 found the first deposits of supernova
matter on Earth1. But it was impossible to date the supernova accurately
from those samples, because the material was distributed through several
different layers of rock.

The team has now analysed a different piece of ocean crust, where the
supernova detritus is concentrated into a clear band of rock that can be
accurately dated. The researchers found small but significant amounts of an
isotope called iron-60 in the rock, which could only have come from a
supernova.

Full Text at Nature:
http://www.nature.com/news/2004/041101/full/041101-5.html

Posted by
Robert Karl Stonjek
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 11/8/04 9:33:33 PM