A vast, flat, "featureless" plain on Mars surprised researchers by revealing a much more tumultuous geologic past than expected, according to a study led by researchers at the University of Arizona. Enormous amounts of lava have erupted from numerous fissures as recently as 1 million years ago, blanketing an area almost as large as Alaska and interacting with water in and under the surface, resulting in large flood events that carved out deep channels.
