While previous studies have suggested that Venus may have been a much more hospitable place in the past, with its own liquid water oceans, a recent study by astrophysicists led by the University of Geneva found that Venus is unlikely to have harboured any ocean anytime in the past.
The researchers simulated the climate of the Earth and Venus at the very beginning of their evolution, when the surface of the planets was still molten. The high temperatures seen in Venus meant that any water would have been present in the form of steam. Using sophisticated three-dimensional models of the atmosphere, similar to those scientists use to simulate the Earth's current climate and future evolution, the team studied how the atmospheres of the two planets would evolve over time and whether oceans could form in the process, a release says.
“Thanks to our simulations, we were able to show that the climatic conditions did not allow water vapour to condense in the atmosphere of Venus,” says Martin Turbet of the University of Geneva and the first author of a paper published in Nature . This means the temperatures never got low enough for the water in its atmosphere to form raindrops that could fall on its surface. Instead, water remained as a gas in the atmosphere, and oceans never formed. “One of the main reasons for this is the clouds that form preferentially on the night side of the planet. These clouds cause a very powerful greenhouse effect that prevented Venus from cooling as quickly as previously thought,” he says in a release.