Astronomers have found a potential sign of life high in the atmosphere of neighbouring Venus: Hints there may be bizarre microbes living in the sulfuric acid-laden clouds of the hothouse planet.
Two telescopes in Hawaii and Chile spotted in the thick Venusian clouds the chemical signature of phosphine, a noxious gas that on Earth is only associated with life, according to a study in Monday’s Nature Astronomy journal.
Several outside experts – and the study authors themselves – agreed this is tantalising but said it is far from the first proof of life on another planet.
As astronomers plan for searches for life on planets outside our solar system, a major method is to look for chemical signatures that can only be made by biological processes, called biosignatures.
Three astronomers in Hawaii decided to look at the closest planet to Earth: Venus. They searched for phosphine, which is three hydrogen atoms and a phosphorous atom.
On Earth, there are only two ways phosphine can be formed, study authors said. One is in an industrial process. (The gas was produced for use as chemical warfare agent in World War I).
The other way is as part of some kind of poorly understood function in animals and microbes. Some scientists consider it a waste product, others do not.
Phosphine is found in “ooze at the bottom of ponds, the guts of some creatures like badgers and perhaps most unpleasantly associated with piles of penguin guano”, Clements said.