Branched graben structures: evidence of a former ocean?
Branched graben structures: evidence of a former ocean?
Depressions up to two kilometres wide and 20 kilometres long intersect, forming a polygonal pattern. The origin of these grabens is complex and possibly indicates they were formed under water. This suggests that the northern lowlands, including Utopia Planitia, may have hosted a standing body of water – possibly even an ocean – early in Mars’s history.