An international team of astronomers, led by Professor Jane Greaves of Cardiff University, today announced the discovery of a rare molecule—phosphine—in the clouds of Venus. On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.
finding that phosphine is present but scarce—only about twenty molecules in every billion.
The astronomers then ran calculations to see if the phosphine could come from natural processes on Venus. They caution that some information is lacking—in fact, the only other study of phosphorus on Venus came from one lander experiment, carried by the Soviet Vega 2 mission in 1985.
Massachusetts Institute of Technology scientist Dr. William Bains led the work on assessing natural ways to make phosphine. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. Natural 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 on Venus, terrestrial organisms would only need to work at about 10% of their maximum productivity, according to calculations by Dr. Paul Rimmer of Cambridge University. Any microbes on Venus will likely be very different to their Earth cousins though, to survive in hyper-acidic conditions.
She comments: “Finding phosphine on Venus was an unexpected bonus! The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% of acid in their environment—but the clouds of Venus are almost entirely made of acid.”
confirming the presence of “life” needs a lot more work. Although the high clouds of Venus have temperatures up to a pleasant 30 degrees centigrade, they are incredibly acidic—around 90% sulphuric acid—posing major issues for microbes to survive there.