Our large Moon is a testimony to the fact that Earth could have been created during a collision between two massive protoplanetary bodies. Could Venus have been created in the same way? Cardiff University scientist Dr Huw Davies believes so. This would be a first step into explaining why Venus, though relatively similar to Earth, having roughly the same size and density, is so dry and so hot.

Venus' dense atmosphere is filled mostly with carbon dioxide and a series of other greenhouse gases, which determined the appearance of a runaway global warming effect that heats up the surface of the planet to temperatures as high as 720 Kelvin. For now, there are no evidence of oceans, continents or plate tectonics.

Dr. Davies argues that such a massive collision may be able to explain these differences, but, at the same time, he recognizes that the theory is flawed. For example, we know that our planet was formed during a mega-collision, due to our large Moon. But Venus has no moons! The explanation for this particular feature would be a head on collision, which does not produce as much debris as in a case similar to that of Earth. Secondly, the lack of water can only be explained by the fact that during a mega-collision, iron would quickly react with water, rendering the planet dry.

But, if we were to consider such a possibility, than Earth would also have to be dry. A dry planet ultimately translates in the lack of plate tectonics, nor continents and life. A third and final evidence towards the possibility that Venus could have been created in a planetary collision, is its odd rotation, but this also could be explained through the total lack of natural satellites. Similar theories have been proposed in the past by astrophysicists, but the lack of a moon forced them to abandon it.