Sep 15, 2020 - Science

What it would mean to find life on Venus

Illustration of the planet Venus in a petri dish

Illustration: Annelise Capossela/Axios

Scientists think they may have found an indicator of life in Venus’ clouds — a discovery that, if confirmed, will cause them to re-examine everything they thought they knew about how life evolves.

The big picture: If life does exist within a small niche of habitability in Venus' temperate layer of clouds, it might mean that life could be even more ubiquitous in the universe than previously expected. The discovery is already fueling calls from scientists who want a mission sent to the nearby world.

  • "If we have Venus also creating life, amidst some completely different scenarios from what we have on Earth, it would be really quite silly to think there's some unique thing about our solar system," Clara Sousa-Silva, an author of the new Venus study and researcher at MIT, told Axios.

Catch up quick: On Monday, scientists announced the discovery of phosphine — a possible sign of life — in the clouds of Venus' upper atmosphere.

  • The gas isn't a sure-fire sign that microbes are floating around in the planet's clouds, but the researchers behind the study haven't yet been able to find another explanation for why the phosphine exists.
  • Future observations will focus on confirming the phosphine detection and scientists are advocating for a Venus probe that might be able to sniff out the gas — and possibly life — in the planet's atmosphere.

The big question: What kind of life could exist within Venus' clouds?

  • Scientists think Venus once was somewhat like Earth, long-lived bodies of water on its surface. But hundreds of millions of years ago, a runaway greenhouse effect took over, leaving the planet shrouded in dense clouds and host to an inhospitable surface.
  • On Venus, microbes or even other creatures living in the clouds could be the last holdouts after a violent reordering of their world's climate — or it could be life that evolved independently in the clouds.
"If there had been life there when it was habitable, maybe that life managed to adapt. Or maybe only the few life forms that could make it into the clouds, they watched a worldwide massacre of every other lifeform they knew, and this is them hanging on to the very end, and we're witnessing this kind of final chapter of life on Venus."
— Clara Sousa-Silva

Yes, but: Even if life is confirmed on Venus, it will still take time and a lot of analysis to figure out its origins.

  • Scientists have long wondered if life could have been seeded throughout the solar system either though meteorites or some other mechanism that spreads material around the solar system.
  • If life came to be on Venus entirely independently of life on Earth, however, that would tell researchers something important about how exactly life evolves, potentially providing answers to a number of questions about the nearby planet's history and evolution.
  • "That's why this has the potential to open a lot of doors that we haven't really appreciated before," planetary geologist Paul Byrne, who wasn't involved in the new study, told Axios.
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