[meteorite-list] Carbon Found To Be Older Than The Solar System

From: star-bits_at_comcast.net <star-bits_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:29 2004
Message-ID: <022720041935.12662.4d6e_at_comcast.net>

<the organic material in the IDP she and her colleagues analyzed probably was
formed in molecular clouds in the interstellar medium before the formation
of the Solar System. The isotopic anomalies are produced by chemical
fractionation at the very low temperatures found in these molecular clouds.

"Our findings are proof that there is presolar organic material coming into
the Solar System yet today," Floss said. "This material has been preserved
for more than 4.5 billion years, which is the age of the Solar System. It's
amazing that it has survived for so long." >

There is nothing in this that is a "proof" that this is presolar. I will concede that it formed in molecular clouds in an interstellar medium. I am not knowledgeable enough (or smart enough ;-)) to debate that point. However there has been no chronological analysis done on this particle. If there had been it would have been mentioned giving a specific age. As the solar system has whipped around the galaxy numerous times it has encountered dusty interstellar mediums at various times which may or may not have predated the solar system. While it may be likely or even highly likely that it came from our own presolar nebula that is not "PROOF" that it is presolar.

    So, you ask, what about presolar diamonds, there is no chronological age for them either? True, however they have been found in meteorites which have been dated to the earliest formation of the solar system and they have a complex history which predates their incorporation into the meteorite. They are presolar.

    Maybe I am wrong, but a claim of "proof" of presolar existance in this case seems a bit premature to me.

--
Eric Olson
ELKK Meteorites
http://www.star-bits.com
> 
> 
> Contact: Tony Fitzpatrick
> tony_fitzpatrick_at_wustl.edu
> 314-935-5272
> Washington University in St. Louis
> 
> Carbon found to be older than the Solar System
> 
> For the first time, researchers have identified organic material in
> interplanetary dust particles (IDPs), gathered from the Earth's
> stratosphere, that was made before the birth of our Solar System.
> 
> The material was identified on the basis of its carbon isotopic composition,
> which is different from the carbon found on Earth and in other parts of the
> Solar System. Isotopes are variations of elements that differ from each
> other in the number of neutrons they have, making them similar chemically
> but different physically.
> 
> Christine Floss, Ph.D., senior research scientist in Earth and Planetary
> Sciences and Physics at Washington University in St. Louis, said that the
> organic material in the IDP she and her colleagues analyzed probably was
> formed in molecular clouds in the interstellar medium before the formation
> of the Solar System. The isotopic anomalies are produced by chemical
> fractionation at the very low temperatures found in these molecular clouds.
> 
> "Our findings are proof that there is presolar organic material coming into
> the Solar System yet today," Floss said. "This material has been preserved
> for more than 4.5 billion years, which is the age of the Solar System. It's
> amazing that it has survived for so long."
> 
> The finding helps in understanding the Solar System's formation and the
> origin of organic matter on Earth. The work was published in the Feb. 27,
> 2004 issue of Science, and was supported by NASA grants.
> 
> Over the past 20 years, researchers have found isotopic anomalies in
> nitrogen and hydrogen from IDPs but never before in carbon. Floss said one
> of the reasons for this was the limitations of earlier instruments. She and
> her colleagues used a new type of ion microprobe called the NanoSIMS, which
> enables researchers to analyze particles at much greater spatial resolution
> and higher sensitivity than before. Until recently, ion probes could only
> measure the average properties of an IDP. In 2000, with help from NASA and
> the National Science Foundation, the University bought the first
> commercially available NanoSIMS. Made by Cameca in Paris, the NanoSIMS can
> resolve particles as small as 100 nanometers in diameter. A hundred thousand
> such particles side-by-side would make a centimeter. Typical sub-grains in
> IDPs range from 100 nanometers to 500 nanometers.
> 
> "The question has always been: Why don't we see any unusual carbon isotopic
> compositions?" Floss said. "The thinking was if the nitrogen and hydrogen
> isotopic anomalies are formed in the same regions of space, it was logical
> to expect unusual carbon isotopic compositions as well. One school of
> thought was that there were different fractionation processes with carbon in
> opposite directions, that cancelled out any anomalies produced. Another
> possibility was that the nitrogen and hydrogen might have been produced in
> phases that weren't originally organic - that the organic material itself
> was formed in the solar system and basically inherited the hydrogen and
> nitrogen isotopic compositions from some precursor material. But our
> isotopic analysis shows that the organic material was formed before the
> Solar System existed and was later incorporated into the IDP."
> 
> Floss and Frank Stadermann, Ph.D., Washington University senior research
> scientist in Physics, worked with colleagues at Lawrence Livermore National
> Laboratory in drawing their conclusions.
> 
> "A lot of IDPs come from comets," Floss said. "It makes sense that organic
> material would be preserved in a very cold environment, such as where comets
> form at the edge of the Solar System. For something to stay this pristine
> and primitive, one can assume that it came from that kind of environment."
> 
> Floss said it's estimated that, over a million years, about a centimeter of
> carbonaceous material comes in the form of such cosmic dust and a
> significant amount of that material may be presolar in origin.
> 
> Floss said that her work builds on the pioneering work of the late Robert
> Walker, Ph.D., professor of Physics at Washington University. Walker was
> instrumental in the acquisition of the NanoSIMS and in the 1980s made
> landmark studies verifying the extraterrestrial origin of such stratospheric
> dust particles.
> 
>                                      ###
> 
> 
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Received on Fri 27 Feb 2004 02:35:51 PM PST