Free Astronomy Magazine November-December 2020

12 NOVEMBER-DECEMBER 2020 ASTROCHEMISTRY such an information repos- itory, were identical to that of the bases and pair- ings (“A-T” and “G-C”) of life on Earth, it would be easier to accept that either the Venus life or the Earth life came first and one ended up establishing a foothold on the other planet − remembering that early Venus, like early Mars, may have been more hospitable to the chemical processes that began the tree of life we see on Earth today, and that Earth might have be- come the unanticipated beneficiary of eons of fundamentally different chemical processes else- where. If Venusian genetic material were similar, but not quite like DNA, did a small number of resilient extremophiles from Earth/Venus survive the long, cold trip to Venus/Earth and begin to incorporate similar molecular fragments, or have we possibly learned that a stable chemical information reposi- tory (like DNA) now is even more estab- lished as at the core of biological life? If Venusian genetics was fundamentally dif- ferent from that on Earth and there was no possible way that stochastic chemical processes could have converted one form into another after some ancient pansper- mic event, then the case for an entirely sep- arate evolutionary course becomes the accepted theory until future studies can challenge the separate-evolution theory. In the Nature Astronomy paper, the au- thors take known non-biological processes for phosphine production, including from the known chemistry of the atmosphere and surface of Venus, to further argue for A n artist’s vi- sion of the volcanism and hazy atmosphere on the rocky Ve- nusian surface. [ESA/AOES] On the left, the “scorpion” ap- peared in the im- ages taken by the Venera 13 lander, about 90 minutes after landing, and noticed by Leonid Ksanfo- maliti. It was ac- tually an image processing arti- fact. [Roscosmos]