Promising sign of life on Venus might not exist after all

Astronomers recently found a tantalizing hint that life could be wafting through the clouds shrouding Venus. But it seems the hunt for extraterrestrial life is far from over, as new research is already calling that discovery into question.

The detection of phosphine gas in Venus’s atmosphere, announced last month, ignited a firestorm of speculation about whether the gas could be produced by alien microbes on the planet, where NASA is currently considering sending a spacecraft. However, three independent studies now have failed to find evidence of phosphine in the Venusian atmosphere.

One of the groups used archival observations to search for signs of the gas in the planet’s clouds, and didn’t find it.

“They’re saying they don’t see the phosphine. That’s really problematic,” says Conor Nixon, a planetary scientist at NASA’s Goddard Space Flight Center who did not participate in the analysis. The study has been peer-reviewed and accepted for publication in Astronomy & Astrophysics.

Two other groups reprocessed the discovery team’s original data and also couldn’t find evidence for phosphine.

But detecting a faint signal from a specific molecule on another planet is a complex process, and the original study authors are not surprised that other scientists are taking a closer look at their work.

“This is normal. This is what science looks like. If this was data that you could have just looked at with the naked eye and seen phosphine, it would have been discovered a long time ago,” says Clara Sousa-Silva of the Harvard-Smithsonian Center for...