Humans are still dreaming about finding extra-terrestrial life in Solar system. This is one of the reasons we are looking at Mars with such utmost curiosity. However, there is another planet that could be harbouring some kind of forms of life. And as bizarre as that sounds it is Venus. A study published in Astrobiology hypothesized that dark spots in Venus atmosphere could be bacterial colonies.
Venus was never one of the candidates to look for life in. Conditions there are extremely rough. In fact, so rough that even human-made probes can’t stand the pressure and heat and break down almost instantly. However, if you look at Venus through a telescope you will notice some dark spots in its atmosphere and we don’t really know what those are. It could be some dust, it could be some unknown gas composition, but it could also be a complex bacterial colony, surviving high above the surface of the planet. But how can we research these dark clouds?
Scientists came up to that hypothesis because these dark clouds are at quite high altitude. This, of course, doesn’t mean much, but bacterial colonies could avoid some of the horrendous conditions of the surfaces of Venus. Furthermore, they could use sunlight as a source of energy, which could explain why they are dark in colour. Actually, it is not even an entirely new hypothesis – Carl Sagan back in 1967 argued that some life forms could be living in the clouds of Venus. Now scientists looked through bacteria on Earth and found several species that could survive the conditions that would be found at high altitude in Venus. But in order to confirm or reject this hypothesis we would have to send a drone which would take samples of Venus atmosphere and maybe even pass through one of those dark spots.
Venus certainly had time to evolve life. Scientists estimate that for around 2 billion years Venus had hospitable conditions for life and even had liquid water. Even Mars didn’t have liquid water for so long. Of course, now Mars actually seems to be a more hospitable environment, even if chances to find life in the Red planet are quite small.
Meanwhile Venus looks like hell. It is the second planet from the Sun, similar in size to Earth. 96.5 % of Venus atmosphere is carbon dioxide and another 3.5 % is nitrogen. Venus is just a one giant greenhouse, where temperatures rise to 462 degrees Celsius. Furthermore, even atmospheric pressure on Venus is 93 times stronger than on Earth. However, of course, at high altitude it is much less of a problem.
But will we ever find out for sure what those dark spots in Venus clouds are? Maybe, if scientists can develop a drone capable of taking and analysing samples from Venus atmosphere. But you should not expect that to happen anytime soon, even though it would be a breath-taking discovery.