Carbon found to be older than the solar system
ORGANIC MATERIAL in the interplanetary dust particles (IDPs), gathered from the planet Earth's stratosphere that was made before the birth of our solar system has been identified by American researchers.
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 possess, making them very much similar chemically but different physically.
The organic material in the IDP that Christine Floss and her colleagues, at Washington University in St. Louis, analysed was probably formed in molecular clouds in the interstellar medium before the formation of the Solar System.
Chemical fractionation at the very low temperatures found in these molecular clouds produces the so called isotopic anomalies.
``Our findings are a strong proof that there is presolar organic material coming into the Solar System yet today,'' said Floss and his team. `
`This material has been preserved for more than about 4.5 billion years, which is the age of the solar system. It is highly amazing that it has survived for so long a period.''
The finding further helps in understanding the solar system's formation and the origin of organic matter on Earth. The work was published in the journal Science.
``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, which 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.''
``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."
Over a million years, about a centimetre of carbonaceous material comes in the form of such cosmic dust and a significant amount of that material may be pre-solar in origin Floss estimates.
— Our Bureau
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