A TEAM of astronomers has announced the discovery of the peculiar gas, phosphine, in the atmosphere of Venus. This has sparked off wonderful speculations about the possibility of microbial life in the clouds of our sister planet.

Though the surface of Venus is far too hot and dry for any imaginable life, the clouds high above its thick atmosphere are at a temperature and pressure not all that different from Earth’s. That coincidence first led to suggestions more than 50 years ago that microbes might survive there. Since then, a series of speculative papers have explored just what sort of bugs those could be.