Cold, Wet Early Mars

By looking at the geochemistry of the lowlands in the northern hemisphere of Mars compared to land in the southern hemisphere, a new study suggests early Mars was cold and wet, complete with an ocean over the northern polar region.

The study splits the difference between the two current leading pictures of early Mars-- one cold and dry, the other warm and wet. The new picture envisions an ocean of near freezing water flanked by glaciers and with perhaps part of the ocean iced over.