In the frozen silence of space, more than 1,300 light years from our blue planet, may be one of the most fascinating stories in modern science. At the heart of the constellation of Orion, a young star called V883 Orionis delivers its most intimate secrets to earthly telescopes, revealing a chemical treasure of capital importance to understand the origin of life.
Complex chemistry with stars cradle
What the researchers discovered defies the understanding: no less than 17 complex organic molecules swirl in the disc of matter which surrounds this emerging protoetoile. Among them, glycol ethylene and glycolonitrile, two chemical compounds that biologists know well since they constitute the direct precursors of the fundamental elements of DNA and RNA.
This discovery, fruit of the meticulous work of a team led by Abubakar Fadul of the Max Planck Institute of Astronomy, represents much more than just scientific curiosity. It literally upsets our understanding of the distribution of organic matter in the cosmos and opens up vertiginous perspectives on the potential omnipresence of life.
The revolution of an established theory
Until now, the scientific community adhered to a relatively pessimistic model concerning the survival of organic molecules during stellar formation. Astronomers considered that violent processes accompanying the birth of stars – plasma eruptions, intense radiation, extreme temperatures – inexorably destroyed most of the complex organic compounds accumulated in interstellar clouds.
This vision implied that only rare planetary systems, under exceptionally favorable conditions, could locally reconstruct these essential chemical bricks. Life then appeared as a phenomenon of extraordinary rarity, the fruit of almost miraculous circumstances.
Kamber Schwarz, co-author of the study and renowned astrochemist, perfectly sums up the paradigm which has just collapsed: ” It now seems to be the opposite of what we thought. Our observations suggest that the protoplanetary discs inherit directly with complex molecules from anterior phases, and that their chemical enrichment continues even during the formation of the system. »
Alma’s piercing eye reveals the invisible
This conceptual revolution would not have been possible without the extraordinary performance of the Large Millimeter/Submillimeter Array, better known by the acronym. This network of 66 radiotelescopes, perched in the aridity of the Chilean desert, has an unequaled sensitivity to detect the radio signatures of organic molecules in space.
It is thanks to this exceptional instrument that researchers were able to identify the emission lines characteristic of these 17 organic molecules. A remarkable technical feat, made possible by an unexpected natural phenomenon: the periodic eruptions of V883 Orionis generate enough heat to enhance the ice of the protoplanetary disc, releasing in space the organic compounds which were trapped there.
This artist’s view shows the planetary disc around the star V883 Orionis. In its external part, volatile gases are frozen in the form of ice, containing complex organic molecules. An energy explosion from the star heats the internal disc to a temperature that evaporates the ice and releases complex molecules, allowing astronomers to detect it. The inserted image shows the chemical structure of the complex organic molecules detected and presumed in the protoplanetary disc (from left to right): propionitrile (ethyl cyanide), glycolonitrile, alanine, glycine, glycol ethylene and acetonitrile (methyl cyanide). Credit: ESO/L. Calçada/t. Müller (MPIA/HDA)
A chemical continuum of space in planets
The implications of this discovery, reported in he Astrophysical Journal
Letters, far exceed the framework of pure astronomy. If these results are confirmed, they establish the existence of direct chemical continuity between the vast interstellar molecular clouds and the over -planned planetary systems. This “straight line of chemical enrichment”, to use Fadul’s terms, would radically transform our perception of the probability of emergence of life in the universe.
Instead of being a extremely rare cosmic accident, life could represent an almost inevitable consequence of the natural chemical evolution of interstellar matter. Each new planetary system would thus inherit a molecular heritage already rich in organic precursors, exponentially multiplying the chances of appearance of living forms.
To new exploration horizons
Caution, scientists insist on the preliminary nature of their conclusions. High resolution observations are necessary to definitively confirm the presence of these molecules, and in -depth studies will have to assess their resistance to extreme conditions of stellar training.
But enthusiasm is palpable in the scientific community. Fadul already evokes the next steps: ” We should explore other regions of the electromagnetic spectrum to detect even more advanced molecules. Who knows what we could discover?«
This question resonates as an invitation to dream and exploration, recalling that the universe has not finished surprising us and that life, perhaps, awaits us at the bend of each nascent star.
