NRPLUS MEMBER ARTICLE O n September 17 a group of scientists using Earth-based telescopes announced that they had detected phosphine in the atmosphere of Venus. On Earth, phosphine is almost always produced by microbial activity. While geological processes are known that can, in principle, produce phosphine, the concentrations of the gas found on Venus, while small, were nevertheless much too high to be attributable to such sources. So how could the phosphine hove gotten there? The simplest explanation is life.

But how is that possible? Venus is nearly a twin for Earth in size and 30 percent closer to the Sun. Because it is closer …