Mars is an arid desert bombarded with cosmic rays, carcinogenic UV radiation and subjected to very large temperature differences between day and night (a hundred degrees around a very low average close to -55 ° C). Its very oxidizing atmosphere – which explains in passing the red tint of its soil – constitutes an additional obstacle so that life can reasonably survive there.
But this has not always been the case. About 4 billion years ago, the red planet was not yet red, and an ocean may even have covered up to a third of its surface. A thick atmosphere rich in carbon dioxide allowed to keep its heat, making possible the existence of liquid water. At the same time, a global magnetic field still had to protect this atmosphere from the solar wind and high energy cosmic particles which tend to break up complex molecules.
How long has Mars been welcoming? Has life had time to make its appearance?
We still find today the vestiges of these ancient times
. (tagsToTranslate) March (t) Space (t) News (t) news (t) Sciences (t) astronomy (t) scientific news (t) human sciences (t) ecology (t) planet (t) zoology (t) flora and fauna