One of the most fascinating theories about the origin of life on Earth is that of panspermia, which comes to say that life, or at least some of its essential components, would have originated outside of space. Later, these first organic molecules would have reached the earth’s surface aboard meteorites.
Although it remains a theory, the truth is that in recent years evidence has been accumulating that panspermia does not seem like such a far-fetched idea. Advances in technology and the development of increasingly precise detection instruments are allowing scientists to analyze in great detail the composition of the space around us. The latest finding, carried out by an international team of scientists, is published in the journal PNAS and describes for the first time the detection of ethanolamine (NH2CH2CH2OH) in space. This molecule contains four of the six chemical elements that are considered essential for life: oxygen, carbon, hydrogen and nitrogen. In addition, ethanolamine is part of the phospholipids, molecules that make up cell membranes , which were crucial in the origin and early evolution of life on Earth: they are responsible for maintaining stable conditions inside cells, protecting, both the genetic material and the metabolic machinery.
“Although the membranes of all cells that exist today are made of phospholipids, there is still a great debate about the nature of the first membranes and the very origin of phospholipids,” explains research leader Victor M. Rivilla, researcher at the Higher Council for Scientific Research (CSIC) at the Center for Astrobiology.
In the center of the Milky Way
The discovery of this important prebiotic molecule has occurred specifically in the molecular cloud G + 0.693-0.027, located near the galactic center using the IRAM radio telescope of 30 meters in diameter of Pico Veleta (Granada) and the 40 meters of the Observatory of Yebes (Guadalajara). “Our results suggest that ethanolamine is efficiently synthesized in interstellar space in molecular clouds where new stars and planetary systems are formed,” the expert highlighted.
The team’s work supports the idea that ethanolamine may have formed in space and later transferred to meteors. Furthermore, experiments simulating chemical conditions on early Earth confirm that this molecule could have contributed to the production of the simplest phospholipids during our planet’s early times.
For Carlos Briones, researcher at CAB-CSIC-INTA and co-author of the study, “the availability of ethanolamine in the primitive Earth, together with fatty acids or alcohols, could have contributed to the evolution of primitive cell membranes. This has important implications no only for the study of the origin of life on Earth, but also on other habitable planets and satellites within the Solar System or anywhere in the Universe “.
Other molecules of astrobiological interest
Ethanolamine is not the first organic molecule precursor of prebiotic chemistry that has been detected in space, and it adds to findings such as that of hydroxylamine or thioformic acid. “Thanks to the improvement in the sensitivity of current and next-generation radio telescopes, we will be able to detect increasingly complex molecules in space that could give rise to the three basic molecular components of life: lipids (which form membranes), nucleic acids RNA and DNA (which contain and transmit genetic information), and proteins (which are responsible for metabolic activity), “says Rivilla. ” Understanding how these prebiotic seeds form in space could be key to understanding the origin of life, ” he concludes.
Referencia: Rivilla et al. 2021. Discovery in space of ethanolamine, the simplest phospholipid head group. PNAS. DOI: 10.1073/pnas.2101314118
