Scientists have discovered possible evidence that there may be life on the planet Venus. Astronomers mostly look towards Mars or certain icy moons for proof of extraterrestrial life in our solar system, dismissing Venus due to its high temperatures and inhospitable atmosphere. But the recently discovered presence of the chemical gas phosphine in Venus's atmosphere suggests that something is living on the planet, most likely alien microbes. That's one possibility, at least. Skeptics suggest that the phosphine may result from some unexplained environmental event on Venus, noting that astronomers still know relatively little about what transpires on the planet. Still, some wonder if this is proof that Venus was once more like Earth than previously believed, despite the planet being considered "Earth's twin" for having approximately the same mass as Earth.
"This is an astonishing and 'out of the blue' finding," Sara Seager of the Massachusetts Institute of Technology tells The New York Times. She's one of the authors of the papers detailing this discovery. "It will definitely fuel more research into the possibilities for life in Venus's atmosphere."
"We know that it is an extraordinary discovery," said Clara Sousa-Silva, a molecular astrophysicist at Harvard University who studies phosphine. She also co-authored the new research papers. "We may not know just how extraordinary without going back to Venus."
Sarah Stewart Johnson of Georgetown University, who did not contribute to the papers, said, "There's been a lot of buzz about phosphine as a biosignature gas for exoplanets recently," referring to the search for life on worlds that orbit other stars. "How cool to find it on Venus. Venus has been ignored by NASA for so long. It's really a shame."
Many in the scientific community believe that Venus was once a planet covered in water and may have had an environment where life could flourish. That's hard for some to imagine, given that Venus seems barren and unlivable now. But the Earth wasn't much different in its pre-human history in that regard. While NASA has more recently focused its efforts on studying Mars, past astronomers, including Carl Sagan, suggested life may exist beneath Venus' thick atmosphere decades ago.
"For the last two decades, we keep making new discoveries that collectively imply a significant increase of the likelihood to find life elsewhere," said Thomas Zurbuchen, head of NASA's science directorate. "Many scientists would not have guessed that Venus would be a significant part of this discussion. But, just like an increasing number of planetary bodies, Venus is proving to be an exciting place of discovery."