If it looks like an impact crater and walks like an impact crater, it may not actually be an impact crater. The Eden Patera basin on Mars has long been classified as an impact crater, but scientists are rethinking the designation based on a fresh look at images and topographic data.
One clue that points to a different origin is the lack of a raised rim around the basin, a feature usually found on impact craters. There are also signs of the ground collapsing, indicating long-ago activity below the surface. If the researchers are right, then this would be the first ancient supervolcano identified on the Red Planet.… Read more