Sep 14, 2020 - Science

Scientists find possible sign of life on Venus

Venus as seen from orbit

Venus as seen from orbit. Photo: JAXA /ISAS/Akatsuki Project Team

Traces of a gas in Venus' clouds could indicate some form of life may exist there, according to a study published today.

Why it matters: Scientists have been musing about the possibility that life exists in Venus' temperate clouds for decades. If confirmed as a sign of life, the finding would open up a new era of science.

What's new: The new study in the journal Nature Astronomy reports the detection of phosphine — a possible signature of life — in Venus' atmosphere for the first time.

  • The researchers found the gas — which can be produced by some microbes that live in animal intestines on Earth — using two different telescopes: ALMA in Chile in 2019 and the James Clerk Maxwell Telescope in 2017.
  • The scientists behind the study aren't suggesting the phosphine discovery is proof positive of life, but they haven't been able to find a better explanation for why the gas exists in the abundances it does on the planet.
"So far we've done everything we can, which is go through all the things that it isn't. We've thought of every possible mechanism, plausible or implausible, that could make phosphine and we cannot come up with any."
— Clara Sousa-Silva, an author of the study and researcher at MIT, to Axios

But, but, but: It's still possible that some as yet unknown geochemistry might be creating the phosphine seen by the telescopes, and there's a long way to go before this detection can be claimed as proof of life on Venus.

  • Scientists will need to advance the findings using other observatories able to peer into Venus' atmosphere and confirm the signal this team found.
  • A mission to Venus' clouds could also help fill in key pieces to the puzzle of whether life exists above the world's surface.
  • "This is a very provocative discovery, and I think you'll see more and more papers in the next couple years building on this as a piece of a story," James Garvin, a planetary scientist at NASA who is not affiliated with the study, told Axios.

How it works: Scientists think that millions of years ago, Venus actually had oceans of liquid water like Earth.

  • At some point, however, a runaway greenhouse effect turned Venus into the inhospitable world it is today, with a surface temperature hot enough to melt lead.
  • The planet's temperate cloud layer, however, ranges between 30°F to 200°F, making it theoretically possible for some type of tough life to keep hold in the mid-latitudes of the world.

Between the lines: This discovery, whether it is proof of life or not, could be a turning point for the exploration of Venus, which plays second fiddle to Mars.

  • The Red Planet has long been thought to be one of the best places to hunt for extant or extinct life in the solar system, but the discovery of phosphine on Venus could motivate NASA to send its first probe in 30 years to the cloudy planet.
  • "Detecting weird, anomalous chemistry we can't readily explain is in itself a compelling reason — amongst many other existing compelling reasons — to go to Venus to study it," Paul Byrne, a planetary geologist unaffiliated with the study, told Axios.
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