European Spacecraft Spotted Signs of Ancient Ocean on Mars

According to researchers the European Space Agency’s Mars Express spacecraft detected sediments on Mars‘ northern plains that are reminiscent of an ocean floor, in a region that has also previously been identified as the site of ancient Martian shorelines. Mars Express uses a radar instrument, called MARSIS, to probe beneath the Martian surface and search for liquid and solid water in the upper portions of the planet’s crust. The researchers analyzed more than two years of MARSIS data and found that the northern plains of Mars are covered in low-density material that suggests the region may have been an ancient Martian ocean. The idea of oceans on ancient Mars is hardly new, and features reminiscent of shorelines have been tentatively identified in images from various spacecraft and missions. Still, the concept remains controversial.This new investigation comes on the heels of a separate study that found that Mars may have experienced a “super-drought,” making it parched for too long for life to exist on the surface of the planet today. But, scientists working to document Mars’ history have proposed two oceans: one 4 billion years ago when the planet experienced a warmer and wetter period, and one 3 billion years ago when subsurface ice melted after a large impact that created various channels that drained water into areas of lower elevation. According to researchers the more recent ocean would have only been a temporary feature on the Martian surface. The water would likely have been frozen or preserved underground again, or turned into vapor and lifted gradually into the atmosphere within a million years or less. The sediments seen by Mars Express are typically low-density grains of material that have been eroded away by water and carried off to their current location. These results are some of the best evidence yet that there were once large bodies of liquid water on the surface of Mars. The findings are also further proof that liquid water likely played an important role in the geological history of Mars, and the planet’s own evolution.