Yesterday I got an email from Cosmoquest about a science press conference (“presser”) where a new discovery would be announced. With all the new distance-based communication technology anybody could watch, rather than just those in a select room, however large. The event was put on by the Royal Astronomical Society today. I watched it on the Cosmoquest Twitch TV channel. I had never heard of Twitch TV before.

The occasion was that

An international team of astronomers, led by Professor Jane Greaves of Cardiff University, today announced the discovery of a rare molecule – phosphine – in the clouds of Venus. On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.

The discovery was made by spectroscopy using two different radio telescopes. The significance of this is that the production of phospine by purely chemical processes is very unlikely in the atmosphere of Venus. The team looked at every possible chemical reaction they could think up, and failed to find any that could come close to producing the observed amount of phospine.

The surface of Venus is hellishly hot: 740°K = 467°C = 872°F. Thanks to the CO₂ greenhouse effect, it is much hotter than Mercury, even though that planet is considerably closer to the Sun. However, 50-60 km above the surface there is a “temperate zone” where life of some form might be possible.

Phosphine is a very reactive substance. Back at Chicon 7 I heard Br. Guy Consolmagno say that if you are looking for life you want to find some highly reactive chemicals. Here on Earth Oxygen fills that role very nicely. You really do not want stability. Equilibrium is death.

The official paper Phosphine gas in the cloud decks of Venus is now available. It is not behind a paywall now and may be kept free. However, I downloaded a pdf just in case.

After the official presentation came the question period. Rather than the usual media, most of the questions were taken from science journalists and communicators, including Ethan Siegel, Christian Ready, and Pamela Gay. Hence the questions were quite good, and got detailed answers.

The scientific team emphasized the tentative nature of their findings. There may be some as yet unknown chemical process that could produce the observed amounts of phosphine. They did not say they had discovered life on Venus, though they seemed to dread what the popular news media may say. FWIW, the Economist and Cosmos articles are quite good.