Did we just find life on Venus ?

After the moon, Venus is the brightest object in the night sky, gleaming like a tiny diamond in the darkness. The planet is so radiant because of its proximity to Earth, but also because it reflects most of the light that falls across its atmosphere, more than any other world in the solar system. 

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. Phosphine molecules found on Earth are primarily a result of human industry or the actions of microbes that thrive in oxygen-free environments.

“As crazy as it might sound, our most plausible explanation is life,” Clara Sousa-Silva, a molecular astrophysicist at MIT and one of the authors of the new study, told me.

Before everyone starts screaming, I need to emphasize that the discovery of phosphine molecules in Venus’s atmosphere does not mean that scientists have found proof of alien life. The detection is simply evidence of a phenomenon scientists can’t yet explain. The phosphine could be created by some form of life, or it could be forged by a chemical process that scientists just haven’t seen before.

The researchers are not claiming life has been detected on the second planet from the sun. But the observations suggest at least the possibility of microbial activity in the upper layers of Venus' atmosphere, well away from the planet's inhospitable surface.

"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. "And the reason for our excitement is that phosphine gas on Earth is made by microorganisms that live in oxygen-free environments. And so there is a chance that we have detected some kind of living organism in the clouds of Venus."

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.

In the planet's upper atmosphere, however, temperatures are much more hospitable. Despite the acidic nature of the clouds, scientists have speculated it may be possible for alien microbes to exist.