Ancient Mars May Have Been More Habitable Than We Thought
http://io9.com/ancient-mars-may-have-been-more-habitable-than-we-thoug-1668711727
Data collected by the Curiosity Rover suggests Mars once featured a moderate climate capable of fostering lakes of liquid water and even a vast sea, and that this climate could have extended to many parts of the Red Planet.
NASA's Curiosity Rover is currently investigating the lowest sedimentary layers of Mount Sharp, a section of rock 500 feet (150 meters) high known as the Murray formation. Observations taken by the robotic probe suggests the mountain was produced by sediments deposited in a large lake bed over tens of millions of years. The observation strongly suggests that ancient Mars maintained a long-lasting water-friendly climate.
According to NASA scientists, it's an hypothesis that's challenging the notion that warm and wet conditions were transient, local, or only underground. It now appears that Mars' ancient, thicker atmosphere raised temperatures above freezing globally, but NASA scientists aren't entirely sure how the atmosphere produced the required effects....
The new discovery has major implications for our understanding of the Red Planet. It suggests Mars was far warmer and wetter in its first two billion years than previous assumed. It also suggests that Mars experienced a vigorous and dynamic global hydrological cycle that involved rains or snows to maintain such moderate conditions.