Airborne life on Venus would be unusual, but perhaps not as strange one might think. Just last month, inspired by the upcoming phosphine findings, MIT astronomer Sara Seager and some of the other coauthors of this new study published a paper about a possible life cycle on Venus that could sustain organisms in the Venusian clouds, emphasizing the fact that the clouds present more temperate and habitable conditions for life. She suggests that life on Venus could exist in droplets at high altitudes that evaporate and leave dried-up spores hanging in the atmosphere. Unlike Earth, Venus’s clouds are permanent—providing a more stable environment where these spores would dry out and fall to lower altitudes, rise back up in growing droplets in the cloud layer, and rehydrate to continue their life cycle. The goal, says Seager, was to help “plug a hole” in thinking about this environment.
The phosphine in Venus’s clouds was found by Jane Greaves, a planetary scientist with Cardiff University, and her team. They studied the planet using the James Clerk Maxwell Telescope (JCMT) in Hawaii, and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Both observe in submillimeter wavelengths that stretch from far infrared to microwave, which allows scientists to more closely characterize the chemical composition of the atmosphere.
The team found traces of phosphine at a concentration of about 20 parts billion. The data suggests the gas is present in regions closer to the equator and at altitudes of about 55 kilometers, where temperatures are relatively cool (about 30 °C) and the pressure is actually similar to Earth’s. “That suggests it’s part of the global circulation pattern of the atmosphere, where gas sinks before it travels as far as the poles,” says Greaves.
Phosphine is created from phosphorus with three hydrogen atoms. On Earth it is