In order for organic molecules to form, which are those that contain carbon atoms and therefore can be used by cells to make life, very specific conditions must exist , since the universe is composed mainly of hydrogen, and to a lesser extent measured by helium and oxygen.
Scientists believe that it is in interplanetary dust and in the crevices of large rocks that solar radiation and radiation from outer space can interact to synthesize first simple organic molecules and then more complex organic molecules. Did these molecules that have made life possible on our planet form on Earth or did they get here carried by comets that crashed against our surface? A study by an international team, with the participation of scientists from the CSIC, has published in the journal Science the discovery of organic molecules that could be precursors of life on the surface of a comet.
This has been possible thanks to the action of the Philae module, which is part of the Rosetta mission, of the European Space Agency (ESA). Philae has discovered four substances on the surface of comet 67P / Churyumov-Gerasimenko that until now have never been found on these celestial bodies. According to Guillermo Muñoz Caro, researcher at the Astrobiology Center, which depends on the Higher Council for Scientific Research (CSIC) and the National Institute for Aerospace Technology (INTA), “some of the organic molecules found in the comet’s dust are considered precursors of the life, since they are involved in the formation of essential amino acids or nucleic bases.
Furthermore, four of them (methyl isocyanate, acetone, propanal, and acetamide) had never been seen before in comets. The results of the study reinforce the theory that comets formed from ice-coated dust grains in the large cloud that later formed the Solar System. In addition, they are important for the study of the origin of life on Earth , because they could help to understand if it is possible that the great bombardment of comets that the planet suffered 3.800 million years ago supposed the arrival of the precursors of life.
In the research, led by Fred Goesmann of the Max Plank Institute for Solar System Research, the comet’s composition has been analyzed using a device designed to identify organic compounds present both in the vicinity of the body and in the ground. Thus, after Philae bounced and then landed on 67 / P, they detected the presence of 16 organic compounds.
Several had nitrogen, one of the main elements of living things. The presence of these complex organic molecules that have been found in the interior of 67 / P , is an indication about the formation of comets. The reason is that these substances can only form when they interact with ultraviolet radiation from the Sun and with cosmic rays from space, which can only occur near the surface.
Therefore, one explanation for finding them in the 67 / P nucleus is that it was formed by the aggregation of dust grains that millions of years ago were bathed in radiation. Philae , the Rosetta mission module, was the first human artifact to land on a comet. After bouncing and landing on the surface, it ran out of batteries and fell asleep for seven months. Goesmann believes they hope to continue collecting data with a dropper.
