An article published in the journal “Nature Astronomy” reports the discovery of phosphine in the clouds of the planet Venus. A team of researchers led by astrophysicist Jane Greaves of the British University of Cardiff used the James Clerk Maxwell Telescope (JCMT) in Hawaii and the ALMA radio telescope to probe the Venusian atmosphere. The concentration of phosphine detected is about twenty parts per billion, which may seem little, but as far as we know only anaerobic bacteria can produce it in that amount. For this reason, phosphine is considered a biological signature in the study of the atmospheres of exoplanets even if at the moment it’s not possible to completely rule out an abiotic process that can produce phosphine in the conditions of Venus’s atmosphere.