Ancient groundwater carved a 1300-km Martian channel in Shalbatana Vallis
ESA’s Mars Express highlights Shalbatana Vallis, a 1300-km, water-worn channel near Mars’ equator formed about 3.5 billion years ago by groundwater floods. The image reveals winding valleys, chaotic terrain, and hints of past lava flows and volcanic ash, with nearby Chryse Planitia—a region some scientists speculate may have hosted an ancient Martian ocean. The mission’s HRSC data continue to map Mars in 3D and color, deepening our understanding of its watery past.