[meteorite-list] And the Science abstract on the Bizzarro study

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Fri, 25 May 2007 00:49:38 -0500
Message-ID: <85uc53dcoioq8n2ro7assn071kgj1h8d90_at_4ax.com>

No mention of square planetesimals...

http://www.sciencemag.org/cgi/content/abstract/316/5828/1178

Evidence for a Late Supernova Injection of 60Fe into the Protoplanetary Disk
Martin Bizzarro,1,2* David Ulfbeck,1 Anne Trinquier,1 Kristine Thrane,1 James N.
Connelly,1,3 Bradley S. Meyer4
High-precision 60Fe-60Ni isotope data show that most meteorites originating from
differentiated planetesimals that accreted within 1 million years of the solar
system's formation have 60Ni/58Ni ratios that are 25 parts per million lower
than samples from Earth, Mars, and chondrite parent bodies. This difference
indicates that the oldest solar system planetesimals formed in the absence of
60Fe. Evidence for live 60Fe in younger objects suggests that 60Fe was injected
into the protoplanetary disk 1 million years after solar system formation, when
26Al was already homogeneously distributed. Decoupling the first appearance of
26Al and 60Fe constrains the environment where the Sun's formation could have
taken place, indicating that it occurred in a dense stellar cluster in
association with numerous massive stars.

1 Geological Institute, University of Copenhagen, ?ster Voldgade 10, DK-1350,
Denmark.
2 Geological Museum, University of Copenhagen, ?ster Voldgade 5-7, DK-1350,
Denmark.
3 Jackson School of Geosciences, University of Texas at Austin, Austin, TX
78712, USA.
4 Department of Physics and Astronomy, Clemson University, Clemson, SC
29634?0978, USA.


* To whom correspondence should be addressed. E-mail: bizzarro at geol.ku.dk
Received on Fri 25 May 2007 01:49:38 AM PDT