Billions of years ago, it rained on Mars. The water collected in valleys and rivers, filled and spilled over the rims of craters, and was funneled into canyons, perhaps even making its way to a large ...

For the first time, scientists have created a detailed map showing huge, continent-sized river drainage systems on Mars. These ancient river networks date back billions of years, to a time when Mars ...

Ancient Mars is coming into sharper focus as a planet laced with rivers, deltas and vast drainage basins, and that new map of its watery past is rapidly reshaping where scientists intend to look for ...