Scientific American New studies knock down a controversial report observing phosphine in the planet’s atmosphere Print The swirling clouds of Venus, as seen by NASA’s Mariner 10 mission in 1974. Credit: NASA and JPL-Caltech Advertisement Two papers have dealt a fresh blow to the idea that Venus’s atmosphere might contain phosphine gas—a potential sign of life. The claim that there is phosphine on Venus rocked planetary science last September, when researchers reported spotting the gas’s spectral signature in telescope data. If confirmed, the discovery could mean that organisms drifting among Venusian clouds are releasing the gas. Since then, several studies have challenged—although not entirely debunked—the report.