Astronomers May Have Found a Signature of Life on Venus

The search for life beyond Earth has largely revolved around Mars, our rocky red neighbor.

Now, in a surprising twist, scientists at the Massachusetts Institute of Technology and other institutions have observed what may be signs of life in the clouds of our other, even closer planetary neighbor: Venus.

Researchers made the detection using the Atacama Large Millimeter Array in Chile and the James Clerk Maxwell Telescope in Hawaii. If any observation, of Venus, is indeed associated with life, it must be an "aerial" life-form in Venus' clouds -- the only habitable portion of an otherwise a scorched and inhospitable world. The astronomers detected a spectral fingerprint, or light-based signature, of the gas phosphine in Venus' atmosphere. Scientists had previously shown that this gas can only be produce by a living organism.

The MIT team followed up the new observation with an exhaustive analysis to see whether anything other than life could have produced phosphine in Venus' harsh, sulfuric environment. Based on the many scenarios they considered, the scientists conclude that there is no explanation for the phosphine detected in Venus' clouds other than the presence of life. "It's very hard to prove a negative," says MIT researcher Clara Sousa-Silva. "Now astronomers will think of all the ways to justify the existence of phosphine without life. I will be astounded if they can, because we are at the end of our possibilities to find abiotic processes that can make phosphine." Adds Joe Pesce, a program director in NSF's Division of Astronomy,

This is an interesting and intriguing discovery. It's science in action -- now, moving forward, scientists need to verify and explain the how and the why this life-signature exists on Venus.