by The scientific community has been debating whether there was ever an ocean in the low-altitude northern hemisphere of Mars, and new research has given an answer in the affirmative. In the latest study, researchers created a new topographic map using software developed by the U.S. Geological Survey using data provided by NASA and the Mars Orbiter’s laser altimeter, and discovered more than 6,500 kilometers of river ridges. Analysis suggests that these river ridges are likely eroded river deltas or undersea channel belts, remnants of Mars’ ancient coastline. The researchers explained that the scientific community has long debated the existence of oceans in the low-elevation northern hemisphere of Mars. Using topographic data, they mapped a 3.5-billion-year-old coastline with massive deposits, at least 900 meters thick, covering hundreds of thousands of square kilometers.
