Building blocks of life found in three extraterrestrial objects at once

How did life appear on our planet?Could the building blocks of organic molecules recently discovered in three different meteorites hit Earth billions of years ago? Researchers have long assumed that organic compounds can form in an extraterrestrial environment, but now these assumptions have been confirmed. In a recent study, scientists directly observed a key organic molecule that could be used in the future to create other organic molecules, including those needed to form life. Understanding exactly how organic molecules lead to life is one of the greatest mysteries that scientists have been looking for since time immemorial. Despite the scientific and technological progress and the impressive achievements of mankind, we still do not know how a non-biological chemical process can turn into a biological one. So what can molecules recently discovered in meteorites tell us about the origin of life?

The hypothesis about the possibility of transferring living organisms or their embryos through outer space is called panspermia. Scientists recently found a precursor to prebiotic chemistry in three meteorites.

Meteorites and the chemistry of life

An international team of researchers founda polyheterocyclic organic molecule called hexamethylenetetramine (C6H12N4) (also known as hexamine, aminoform, crystalamine, methenamine, formin and urotropin) in three carbonaceous meteorites: the Murcheson meteorite, the Murray meteorite, and the Lake Tagish meteorite. “By confirming the presence of hexamethylenetetramine in meteorites for the first time, our work confirms the hypothesis that this compound was present in asteroids, the parent bodies of many meteorites,” Dr. Yasuhiro, both from Hokkaido University and his colleagues, quoted The Independent as saying.

Authors of the paper published in the journal NatureCommunications believe that the presence of this molecule in carbon-rich meteorites may have contributed to chemical evolution in a primitive stage on Earth. Let us recall that the presence of organic molecules in the extraterrestrial environment was widely recognized after the discovery of an oxygen molecule near the Churyumov-Gerasimenko / 67P comet, as well as long-term astronomical observations and analysis of carbonaceous meteorites in laboratories.

The chemistry of life is based on organic compounds- molecules containing carbon and hydrogen (they can also include oxygen, nitrogen and other elements). Organic molecules are usually associated with life, but they can be created by non-biological (probiotic) processes, and therefore do not necessarily serve as indicators of life.

A fragment of the Murchison meteorite, one of three carbon-rich meteorites sampled in this study.

And yet, despite extensive research onthe formation of organic molecules in various extraterrestrial media, such as molecular clouds, protosolar nebulae and asteroids, it is still controversial when, where and how these extraterrestrial molecules were formed. According to Japanese and American scientists, soon after the birth of the solar system, many asteroids could be heated by collisions or decay of radioactive elements.

“If some asteroids were enoughwarm and had liquid water, hexamethylenetetramine could break down, resulting in building blocks. These building blocks could react to form other important biological molecules previously found in meteorites, including amino acids, ”the study said.

The authors of the work note that some typesamino acids are used by living organisms to make proteins, which then play a central role both in structures such as hair and in the chemical reactions that feed life itself. Although the variety of organic compounds in meteorites is well documented, many questions remain about the processes by which these compounds were formed. Despite the fact that scientists have already discovered a number of organic compounds in meteorites, it is still unclear how exactly they are able to form - the discovered molecule hexamethylenetetramine (C6H12N4) should help scientists finally answer this question.

Do you want to always be aware of the latest news from the world of popular science and high technologies? Subscribe to our news channel in Telegram so as not to miss anything interesting.

Carbon chondrites

The most important meteorites in this area of ​​research are carbonaceous chondrites - stone meteorites that contain highpercentage of water and organic compounds. In a recent study, scientists developed a method that specifically extracted hexamethylenetetramine from meteorites with minimal damage.

Fragment of a meteorite from Lake Tagish.

They managed to allocate significant amountshexamethylenetetramine and its derivatives from carbonaceous chondrites (Murcheson meteorite, Murray meteorite and Lake Tagish meteorite). They also studied the role of hexamethylenetetramine derivatives in the formation of amino acids in meteorites.

"Although we were unable to draw final conclusionsin this study, the discovery of hexamethylenetetramine and its derivatives in these meteorites will lead to future experiments to understand the origins and chemical processes of amino acids and other prebiotic compounds in the extraterrestrial environment, ”the authors of the study said. Note also that the statement was made just after the Hayabusa2 mission finally delivered extraterrestrial "treasures" into the hands of scientists. My colleague Ramis Ganiev spoke in more detail about this amazing event.