Remnants of 1500 km long river discovered on Mars New astonishing pictures by the European Space Agency have revealed a 1500 km long and 7 kilometre wide river that once ran across Mars. The agency's Mars Express imaged the striking upper part of the remnants of Reull Vallis river on Mars with its high-resolution stereo camera, ESA said in a statement. ...  
01:53 PM, Jan 18, 2013