Phosphine gas, on the other hand, is created on Earth by some microorganisms as they digest organic matter, and so it's considered a possible “biosignature” – which means its detection in the atmospheres of distant planets could be a sign of elementary life.

Why does phosphine mean life?

There is phosphine in the atmospheres of Jupiter and Saturn, for example, but there it is not a sign of life. Scientists think it is formed in the deep atmosphere at high pressures and temperatures, then dredged into the upper atmosphere by a strong convection current.

What is the connection between phosphine gas and the possibility of life on Venus?

The detection of phosphine gas in the clouds of Venus—a possible sign of life—might be due to a fluke in data processing, new analyses suggest. Astronomers recently found a tantalizing hint that life could be wafting through the clouds shrouding Venus.