Was Young Mars Warm and Wet or Cold and Frozen?

 Mars is cold and dry, with a thin atmosphere not even 1% as dense as ours.

Now, that is. The question is, what was it like around 3 billion years ago? Evidence abounds on the surface that plenty of water existed there back then, which also means it had a thicker atmosphere and was warmer, too.

However, a new paper has come out questioning that interpretation of the evidence. Instead of it being warm and wet, the scientists argue, instead it was cold and, well, not dry exactly, but frozen. This is hardly the semi-tropical Earth-like planet that for the past decade or two has been the growing consensus. #Astronomy #Mars https://www.syfy.com/syfywire/was-young-mars-warm-and-wet-or-cold-and-frozen