Astronomers find possible sign of life on Venus - CBS News

Traces of a rare molecule known as phosphine have been found in the hellish, heavily acidic atmosphere of Venus, astronomers announced Monday — providing a tantalizing clue about the possibility of life.

The researchers are not claiming life has been detected on the second planet from the sun.

"We have detected a rare gas called phosphine in the atmosphere of our neighbor planet Venus," said Jane Greaves, a professor at Cardiff University in the United Kingdom and lead author of a report published in Nature Astronomy.

"We are claiming the confident detection of phosphine gas whose existence is a mystery," she said.

But Venus is the victim of a runaway greenhouse effect in which thick clouds in a mostly carbon dioxide atmosphere trap sunlight, producing temperatures at the surface that soar to nearly 900 degrees, hot enough to melt lead.

20 parts-per-million of phosphine have been detected in the temperate clouds of Venus, and its source is not evident.

Greaves' team studied spectra of Venus' atmosphere using the James Clerk Maxwell Telescope in Hawaii and 45 radio telescope antennas in the Atacama Large Millimeter/submillimeter Array in Chile and were surprised to see unmistakable signs of phosphine.

The detection was rewarded with additional observing time on the ALMA array and "in the end, we found that both observatories had seen the same thing, faint absorption at the right wavelength to be phosphine gas, where the molecules are backlit by the warmer clouds below," Greaves said in a statement.

But additional research showed natural sources of phosphine — volcanoes, lightning, minerals blown up into the atmosphere, the action of sunlight — would only generate one ten thousandth the amount actually detected.

The atmosphere of Venus is 90% sulfuric acid, raising "many questions, such as how any organisms could survive," said MIT researcher Cara Sousa Silva.

"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," she said.

"Ultimately, the only thing that will answer this question for us — is there life, is there not life — is actually going to Venus and making more detailed measurements for signs of life and maybe life itself."