Skywatchers across the world viewed the last transit of Venus across the disk of the Sun on June, 5 and got some amazing pictures. It was an awe-inspiring event, provided you had something to safely view the sun with, that happens twice around every hundred and five years or so. Chandra Wickramasinghe at the Universityof Buckingham’s Centre for Astrobiology believes gorgeous pictures taken through solar filters and welder’s masks weren’t all we got though. He believes that the rare event also marked a cyclical transit of microbial life from the upper atmosphere of Venus to Earth.
The surface of Venus is a scorched wasteland, with temperatures exceeding even that of Mercury and an atmosphere so thick that its pressure is roughly 92 times that of Earth. Add in sulfuric acid rain and it’s easy to see why any space probe that has actually managed to land on its surface, hasn’t lasted very long. As deadly and inhospitable to life as the surface of Venus is, some scientists do entertain the idea that microbial life is possible in the upper atmosphere where the temperature is cooler and the pressure far less. It is that very habitat that Wickramasinghe believes aids the transfer of life between Venus and Earth. In a paper for the Journal of Cosmology Wickramasinghe states…
The lining up of the Sun, Venus and Earth and the relative proximity of Venus to Earth offers an easy route for microbes, provided suitable mechanisms exist for lofting cloud particles to high enough altitudes in the atmosphere for them to become entrapped in the solar wind.
Charged bacteria and viruses entering the Earth’s magnetosphere would initially follow magnetic field lines, and their quickest and most direct descent will be near the poles. At other latitudes descent to ground level will depend on the particle size as well as the prevailing meteorological factors and could take from days to months.
Venusian microbes will eventually be included as nuclei of rain drops and mist and be added to the Earth’s biosphere. If they are able to replicate in the Earth’s biosphere, they would certainly have contributed modestly to our planet’s genetic heritage.
Interesting idea, but before you start to worry about suddenly turning into a Venusian space-zombie, just remember that there has never been any actual evidence of life in the upper atmosphere of Venus. There would also have to be a pretty amazing amount of it getting spread like buckshot off of Venus’ atmosphere for it to even stand a shot at getting caught in Earth’s magnetic field… whose sole purpose is to deflect most of the solar wind heading in toward the planet rather than letting it all hit the atmosphere anyway. Now that the idea is out there, I’m sure it will only be a matter of time before we see it again in a SYFY Channel Saturday night movie, though.