[meteorite-list] Chicxulub Asteroid

From: bernd.pauli at paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: 15 Sep 2009 21:32:06 UT
Message-ID: <DIIE.0000002E00004035_at_paulinet.de>

An embarrassed Carl writes:

1. Since there are high levels of iridium, is it safe to assume
    it was a stony asteroid or comet but not an iron?
 
2. If it was an iron asteroid, since it was the size of Mount Everest and
    going at near cosmic speed, would it have gone thru the Earth?

  
Hello Carl and List,

Maybe you remember that Frank Kyte (University of California, Los Angeles) found a tiny,
2.5-4 mm-wide piece of light-colored clay on the bed of the Pacific Ocean. He split it open
and found what he believes to be a fossil meteorite, the possible remnant of the K-T impactor.

The amount of iron, chromium, and iridium it contained nicely fits the ranges of these elements
in carbonaceous chondrites. But Kyte was confronted with one problem: he also found much more
gold in this sample than would be expected in a chondritic meteorite. Kyte was sure it must have
been a stony object because the material he found (or what was left of it) was not porous enough
to have come from a comet.

As for going through the Earth: Although the Mount Everest is a huge chunk of rock,
a 10-15 km chunk of asteroidal material like the K-T impactor can only "scratch" at
the surface of this 12,000+ km planet we call Earth. It takes a much larger impactor
to cause a radical change of a planet's rotation period or its axial tilt.

Well, I know the dinosaurs would vehemently disagree ;-)


Best wishes,

Bernd
Received on Tue 15 Sep 2009 05:32:06 PM PDT