A new study shows there is 30 times the amount of carbon dioxide in the ice cap over the south pole of Mars than previously thought. That suggests a warmer Mars had a thicker atmosphere than it does now, which also means liquid water could have existed on the surface. That, in turn, suggests conditions were better for life on Mars.
The climate of Mars seems to go through a roughly 100,000 year cycle of wet and dry periods. We just happen to be seeing the planet during a dry period. It is interesting to speculate how the history of the development of science and philosophy would have been different had we first encountered Mars during one of its wet periods.