Newly-Identified Geological Feature Points to Vast, Long-Dried Up Ocean in Northern Plains of Mars
A continent-like shelf beneath the Martian surface hints that a vast ocean once covered up to a third of Mars, reshaping the long-running debate over its watery past. This artist’s impression shows how Mars may have looked about 4 billion years ago. Image credit: M. Kornmesser / ESO. While it is widely accepted that Mars…