远古火星或有过北冰洋大小的海洋

Core Insights - A team of planetary geologists from the University of Bern, Switzerland, has found evidence suggesting that ancient Mars may have had an ocean comparable in size to Earth's Arctic Ocean, with coastlines and rivers surrounding it, marking one of the most direct pieces of evidence that Mars was once a "blue world" [1][3] Group 1 - The research integrates vast data from NASA's Mars Reconnaissance Orbiter, the European Space Agency's Mars Express, and the ExoMars mission, with the high-resolution color camera on ExoMars being particularly crucial for capturing surface details that black-and-white images could not discern [3] - The team utilized color imagery combined with topographic data to reconstruct the hydrological history of Mars, effectively acting as a "geological time machine" to trace the evolution of Martian landscapes over billions of years [3] - The focus was on the "Valles Marineris," the longest and deepest canyon system in the solar system, measuring approximately 4,000 kilometers in length, over 600 kilometers in width, and 7 kilometers in depth, with significant geological structures dating back around 3.3 billion years [3] Group 2 - The analysis identified numerous structures resembling river deltas and alluvial fans, which are typical landforms created when rivers deposit sediment into still water bodies like oceans or lakes [3] - A clear ancient coastline was traced, allowing the team to estimate the extent of this ancient ocean, which is believed to be the largest body of water in Mars' history, roughly equivalent in area to today's Arctic Ocean [3] - This discovery enhances the understanding of Mars' evolution and brings new hope for the search for extraterrestrial life [3]