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RGClark
2006-May-14, 04:01 AM
Posted: May 5, 2006
Meteorites Discovered To Carry Interstellar Carbon.
"The tell-tale signs are lots of deuterium and 15N chemically bonded to
carbon," commented co-author Larry Nittler. "We have known for some
time, for instance, that interplanetary dust particles (IDP), collected
from high-flying airplanes in the upper atmosphere, contain huge
excesses of these isotopes, probably indicating vestiges of organic
material that formed in the interstellar medium. The IDPs have other
characteristics indicating that they originated on bodies--perhaps
comets--that have undergone less severe processing than the asteroids
from which meteorites originate."
"The scientists found that some meteorite samples, when examined at the
same tiny scales as interplanetary dust particles, actually have
similar or even higher abundances of 15N and D than those reported for
IDPs. "It's amazing that pristine organic molecules associated with
these isotopes were able to survive the harsh and tumultuous conditions
present in the inner solar system when the meteorites that contain them
came together," reflected co-author Conel Alexander. "It means that the
parent bodies--the comets and asteroids--of these seemingly different
types of extraterrestrial material are more similar in origin than
previously believed."
http://www.sciencedaily.com/releases/2006/05/060505192530.htm

Both the carbon and nitrogen are inferred to be of interstellar origin.
It is notable then that nitrogen in relationship to organic carbon has
been proposed as a signature for extraterrestrial life:

Extraterrestrial Life.
"Fri, 05 May 2006 - When searching for life, most researchers have been
hunting the Solar System for signs of liquid water; past and present.
But geobiologists from the University of Southern California think that
more effort should be spent looking for evidence of nitrogen. Since
nitrogen isn't a major component in rocks and minerals but an essential
component of life, any concentration of this element would strongly
indicate life's fingerprint."
http://www.universetoday.com/am/publish/nitrogen_extraterrestrial.html

It is notable as well that organic nitrogen has been found abundant in
carbonaceous meteorites:

NITROGEN AND CARBON ISOTOPIC MEASUREMENTS OF CARBON NANOGLOBULES FROM
THE TAGISH LAKE METEORITE BY SECONDARY ION MASS SPECTROMETRY.
J. W. Ashley1,2, G. R. Huss1, L. A. J. Garvie1, Y. Guan1, P. R.
Buseck1,3, and L. B. Williams1. 1Department of Geological Sciences,
Arizona State University, Box 871404, Tempe, AZ 85287-1404; 2Minor
Planet Research, Inc., Box 17131, Fountain Hills, AZ, 85269-7131;
3Department of Chemistry/Biochemistry, Arizona State University, Box
871404, Tempe, AZ 85287-1604.
Lunar and Planetary Science XXXVI (2005)
http://www.lpi.usra.edu/meetings/lpsc2005/pdf/2205.pdf


Bob Clark