A “life spy” found on Venus: what phosphine is and why it can reveal the presence of microorganisms

Perhaps there is life on another planet in the solar system: but after years of research on Mars, this time the surprise comes from Venere. Astronomers from the British University of Cardiff, coordinated by Jane Greaves, have identified in the clouds a possible indicator of the presence of life: it is the phosphine, or hydrogen phosphide, a gas that on Earth is produced only industrially or by microorganisms in oxygen-free environments. The discovery was published in the magazine Nature astronomy: the phosphine trace was captured by the James Clerk Maxwell Telescope (JCMT), in Hawaii, and by the Alma antennas of the Southern Europe Observatory (Eso).

“Has been a real success – says Jane Greaves, team leader – to see the first signs of the presence of phosphine in the spectrum of Venus! ”. Confirmation of the discovery required the use of 45 antenna of Alma (Atacama Large Millimeter / submillimeter Array) in Chile, a more sensitive telescope of which ESO (European Southern Observatory) is a partner. Both instruments observed Venus at a wavelength of approximately 1 millimeter, much longer than the human eye can see: only telescopes at high altitude can detect it effectively.

The team international, which includes researchers from United Kingdom, United States of America and Japan, estimates that phosphine is found in the clouds of venus at low concentration, only about twenty molecules per billion. The astronomers tested whether these amounts could come from natural non-biological processes on the planet. Among the hypotheses is the sunlight, boosted minerals up from the surface, volcanoes or lightning, but none of these phenomena could produce enough. These non-biological sources have been estimated to produce at most one ten thousandth of the amount of phosphine seen by telescopes.

According to astronomers, to create the quantity phosphine (made up of hydrogen and phosphorus) observed on Venus, Terrestrial organisms should function at approximately 10% just your maximum productivity. Terrestrial bacteria are known to produce phosphine: they absorb phosphate from minerals or biological material, add hydrogen, and eventually excrete phosphine. Any organism on Venus will likely be very different from its terrestrial cousins, but these could also be sources of phosphine in the atmosphere.