Jane Greaves and Planet Venus

A team of astronomers suggested today that there could be life on Planet Venus.

The team said they have spotted the chemical fingerprint of phosphine, which scientists have suggested may be tied to life, in the clouds of the second rock from the sun.

The finding is no guarantee that life exists on Venus, but researchers say it’s a tantalizing find that emphasizes the need for more missions to the hot, gassy planet next door.

The scientists behind the new research wanted to look for phosphine.

Researchers have recently wondered whether the chemical could be a good bio-signature, a compound astronomers target in looking for life. It should break down quickly in atmospheres that are rich in oxygen, like those of Earth and Venus, and on Earth, when it isn’t being made by human industrial processes, it seems to be found near certain kinds of microbes.

Jane Greaves, an astronomer at the University of Cardiff in the U.K. and lead author of the new research, realized that she could use a telescope she knew well to check for it in the atmosphere of Venus, she told Space.com.

“Looking for it in Venus might be really peculiar, but it’s not hard to do and it wouldn’t take that many hours of telescope time,” Greaves said she thought at the time. “Why not give it a go?” So on five separate mornings in June 2017, the astronomers used the James Clerk Maxwell Telescope in Hawaii to stare at Venus.

And then the observations sat around on a computer for a year and a half, Greaves said, without her managing to find time to study them.

“I thought, well, just before we throw this away, I’ll have a final go at [analyzing the data],” she said. “There was this line and it just wouldn’t go away, and it seemed like it wasn’t imaginary anymore. I was just completely stunned.”

That line is one stripe of a spectrum, a chemical barcode that scientists can read in a telescope’s observations of light. Each chemical has its own unique fingerprint of lines and blank spaces; match enough lines and you can identify a mystery substance.

But the observations in the new research focus on only one of the lines in phosphine’s barcode, Meadows said, so she isn’t quite convinced the new findings represent a conclusive identification of phosphine.

Greaves and her colleagues did arrange to use the Atacama Large Millimetre/submillimetre Array (ALMA) in March 2019 to look for the chemical again and make sure the detection wasn’t just a telescopic hiccup.

ALMA gathered a few hours of data, which also revealed more phosphine than the scientists expected — not a huge amount in the grand scheme of things, but about 20 particles out of every billion, according to the research.

“I was braced for disappointment, but it was amazing,” Greaves said.

That abundance is significantly more phosphine than she had expected to see. The way the telescopes’ observations work, the chemical must have been more than 30 miles (50 kilometers) above the Venusian surface. That’s about the same altitude at which a different recent paper with some shared co-authors suggests microbial life could survive in spore form.

So Greaves and her colleagues set to work considering what might have created all that phosphine: Perhaps volcanoes erupting or lightning striking, or perhaps meteors melting in the atmosphere or winds pulling particles off the planet’s surface. But none of these explanations seemed sufficient to them.

As usual, struggling to make more conventional explanations check out does not mean that scientists think they’ve found life. But the possibility of tiny Venusian bugs has gradually become more plausible — and researchers focused on our neighbouring world say that’s important, whether or not there’s actual life to find.

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