A third of Mars once covered by ocean: study

摘要

A huge, potentially life-giving sea likely covered more than a third of Mars some 3.5 billion years ago, according to a study released recently Spread over an area the size of the Atlantic Ocean, it would have straddled the north pole and contained the equivalent of a tenth of the water on Earth. For decades scientists have argued as to whether the Red Planet once harboured bodies of water big enough to help nourish a true hydrological cycle marked by evaporation and rainfall.