[meteorite-list] NASA finds extra-terrestrial amino-acids in Sudan meteor...

[Bernd V. Pauli]

Hello All,

Rob asked:

"So the obvious question to ask is why anyone thinks that the interior 
of 2008 TC3 was ever heated up to 1100 C? Sure, the *surface* of the 
asteroid got very hot when it entered earth's atmosphere, but how is 
that different from Murchison or any other meteorite-generating fall? 
The interior of 2008 TC3 should never have been above freezing."


Hello Rob and List,

Maybe the National Geographic people confounded the external heat that only affected the outer layers of that presumed rubble pile when Almahata Sitta entered earth's atmosphere with the heat that was produced when source material similar to carbonaceous chondrites was converted into ureilites during a collisional scenario somewhere in the asteroid belt accompanied by subsequent recrystallization and annealing at high temperatures (1160°-1200°C*).

Reference:

*CHIKAMI J. et al. (1996) Ureilite formation process with regard
to the LEW 88774 ureilite (Meteoritics 31-4, 1996, A027-A028).


Cheers and all the best
for 2011 to all of us,

Bernd