The discovery in a meteorite of material characteristic of DNA and RNA molecules and confirmation of its extraterrestrial origin can lead to a total revision of our ideas about the origin and evolution of life both on Earth and in the Universe
An international research team led by Dr. Zita Martins of Imperial College London presented Extraterrestrial nucleobases in the Murchison meteorite in the Earth and Planetary Science Letters of June 15, 2008, confirming for the first time the extraterrestrial origin of key DNA molecules and RNA found in the Marchinson meteorite.
This meteorite was found in Australia in 1969.
In the meteorite, uracil (2,4-dioxopyrimidine) molecules were found, which are a characteristic component of ribonucleic acids and are present in all living cells, and xanthine, which are an intermediate product of the cleavage of nucleic acids to uric acid. Xanthine (2,6-purindione) is a nitrogen-containing oxidation product of purines (adenosine and guanine).
One of the signs that made it possible to judge the extraterrestrial origin of the organic material found in the meteorite was the isotopic structure of the carbon atoms that make up their composition - the anomalously high content of heavy carbon isotopes in the isolated molecules can only be explained by their formation outside the Earth. A different isotopic "signature" is characteristic of the uracil and xanthine molecules formed under terrestrial conditions. There are more and more signs that life not only can exist on other planets, but also be transported over long distances in space, even in relatively highly organized forms.
Thus, an experiment carried out in 2004 on board the Russian spacecraft Foton-M2 showed that all lichen samples of two species that spent over two weeks in total overboard, in space, in an open capsule under the influence of a combination of factors - vacuum, weightlessness, temperature fluctuations within wide limits, as well as cosmic radiation - survived and retained the ability to photosynthesis upon returning to Earth.
In 2007, it was shown that fungi have a specific mechanism for obtaining energy, different from photosynthesis, due to the direct conversion of radiation. The conversion agent is melanin, the role of which in the metabolism of fungi has remained a mystery before. Studies have shown that radiation radiation, which is 500 times higher than the background radiation characteristic of the Earth's surface today, contributes to a significant acceleration of the growth of fungi. Astronomical observations have shown the possibility of synthesizing complex organic molecules directly in space, in gas and dust clouds.
One of the generators of organic matter has already been identified in the solar system - the Cassini probe has discovered that not just water is pouring into space from Saturn's moon Enceladus, but an organic "broth", in which, in particular, it was possible to reliably identify the presence of CO and CO2 molecules.
Another discovery, indicating the possibility of the formation of genetic material and its "delivery" to the Earth, if it is confirmed by further research, can radically change our ideas about the evolution of life on Earth and its origin, as well as about the variety of conditions in which it can develop and emerge. New data on the possibility of the origin of life outside the Earth will be presented on the Research and Development portal - R & D. CNews.
