NASA’s Spirit and Opportunity have been exploring Mars about three times as long as originally scheduled. The more they look, the more evidence of past liquid water on Mars these robots discover. Team members reported the new findings at a news briefing today. About six months ago, Opportunity established that its exploration area was wet a long time ago. The area was wet before it dried and eroded into a wide plain. The team’s new findings suggest some rocks may have gotten wet a second time, after an impact excavated a stadium-sized crater.