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Published Online February 28, 2008
Science DOI: 10.1126/science.1153578

Reports

Submitted on November 29, 2007
Accepted on February 14, 2008

Graphite Whiskers in CV3 Meteorites

Marc Fries 1 and Andrew Steele 1*

1 Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, USA.

* To whom correspondence should be addressed.
Andrew Steele , E-mail: a.steele{at}gl.ciw.edu

Graphite whiskers (GW), an allotrope of carbon that has been proposed to occur in space, have been discovered in three CV-type carbonaceous chondrites using Raman imaging and electron microscopy. The GW are associated with high-temperature calcium-aluminum inclusion (CAI) rims and interiors, the rim of a dark inclusion, and within an inclusion inside an unusual chondrule that bears mineralogy and texture indicative of high-temperature processing. Current understanding of CAI formation places their condensation, and that of associated GW, relatively close to the Sun and early in the condensation sequence of protoplanetary disk materials. If this is the case then it is a possibility that GW are expelled from any young solar system early in its history, thus populating interstellar space with diffuse graphite whiskers. GW have been postulated to play a role in the near infrared dimming of type 1a supernovae, and the thermalization of both the cosmic infrared and microwave background and galactic center dimming between 3 and 9 µm. Our observations along with the further possibility that GW could be manufactured during supernovae, suggest that GW may have significant effects in observational astronomy.


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