The findings support the theory that the building blocks for life were delivered to Earth with comets.
The latest results from the European Space Agency’s Rosetta Orbiter have revealed that Comet 67P/Churymov-Gerasimenko contains rare molecules considered essential for the evolution of living organisms. Rosetta has been circling the comet for nearly two years analysing the composition of the comet and its atmospheric halo using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA).
The findings published May 27th in Science Advances, describes the presence of several important molecules — the amino acid glycine, phosphorus, and other organic molecules — in the dusty halo around Comet 67P/Churymov-Gerasimenko.
Glycine is an important biological molecule, being one of the 20 amino acids that are building blocks of proteins. The molecule is the simplest amino acid, containing the organic compounds carbon, oxygen, nitrogen, and hydrogen, and it’s believed to be the only amino acid that can form without liquid water.
“This is the first unambiguous detection of glycine at a comet,” said Kathrin Altwegg, lead author of the paper, in a media release.
“At the same time, we also detected certain other organic molecules that can be precursors to glycine, hinting at the possible ways in which it may have formed.” Altwegg continued.
It’s not the first time that glycine has been found on a comet. During 2006, NASA’s stardust mission extracted the molecule from samples of Comet Wild 2. The comet samples were returned to earth where the findings were revealed.
Now for the first time, glycine has been detected in outer space using Rosetta’s spectrometry instrument, without having to return the samples to earth, thus eliminating the possibility of contamination.
"Amino acids are everywhere, and life could possibly also start in many places in the universe," Altwegg told Reuters.
In addition to the discovery of glycine in the thin halo of the comet, the instrument also found phosphorus, a key component of cell membranes and DNA.
"The multitude of organic molecules already identified by ROSINA, now joined by the exciting confirmation of fundamental ingredients like glycine and phosphorus, confirms our idea that comets have the potential to deliver key molecules for prebiotic chemistry," said Matt Taylor, Rosetta project scientist, speaking with Phys.org.
"Demonstrating that comets are reservoirs of primitive material in the Solar System, and vessels that could have transported these vital ingredients to Earth, is one of the key goals of the Rosetta mission, and we are delighted with this result." Taylor concluded.
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