Where Did Water on Mars Go? Maybe, Nowhere.
Water on Mars disappeared long ago — or did it? Could Mars still hold onto to vast oceans worth of water?
Mars was once a water world, filled with massive oceans, rivers and lakes. At one time, the Red Planet could have held onto enough water to cover that world with a global ocean between 100 to 1,500 meters (330 to 4,900 feet) deep — about half the volume of the Atlantic Ocean.