Scientists have spotted a possible marker of life on Venus, a planet which has not been a significant part of the search for life because of its extreme temperatures, atmospheric composition and other factors. The astronomers were surprised when they found the presence of a chemical called “phosphine” in the atmosphere of Venus, named after the Roman goddess of beauty.
Doing an analysis of the source of the chemical, the scientists ruled out non- biological sources, according to a paper published in the journal Nature Astronomy on Monday and another paper submitted to the journal Astrobiology.
“When we got the first hints of phosphine in Venus’s spectrum, it was a shock!”, said team leader Jane Greaves of Cardiff University in the UK, who first spotted signs of phosphine in observations from the James Clerk Maxwell Telescope ( JCMT), operated by the East Asian Observatory, in Hawai’i.
Confirming their discovery required using 45 antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, a more sensitive telescope in which the European Southern Observatory (ESO) is a partner.
Both facilities observed Venus at a wavelength of about one millimetre, much longer than the human eye can see — only telescopes at high altitude can detect it effectively. The international team, which includes researchers from the UK, US and Japan, estimates that phosphine exists in Venus’s clouds at a small concentration, only about twenty molecules in every billion.
Following their observations, they ran calculations to see whether these amounts could come from natural non-biological processes on the planet.
Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. These non-biological sources were found to make at most one ten thousandth of the amount of phosphine that the telescopes saw.
To create the observed quantity of phosphine (which consists of hydrogen and phosphorus) on Venus, terrestrial organisms would only need to work at about 10 per cent of their maximum productivity, according to the team.
Earth bacteria are known to make phosphine: They take up phosphate from minerals or biological material, add hydrogen, and ultimately expel phosphine. Any organisms on Venus will probably be very different to their Earth cousins, but they too could be the source of phosphine in the atmosphere.
While the discovery of phosphine in Venus’s clouds came as a surprise, the researchers are confident in their detection. “In the end, we found that both observatories had seen the same thing — faint absorption at the right wave- length to be phosphine gas, where the molecules are backlit by the warmer clouds below,” added Greaves, who led the study published in Nature Astronomy.
With IANS inputs
