The robot, which has been exploring Mars for almost six years, discovered new organic compounds and cycles of methane that could point to life on Mars. _____________________________________________________________________________ Since 2012, the Curiosity rover has been exploring Mars near a place called Mount Sharp. The robot has found chemical traces that could indicate this place was watery billions of years ago—and could have supported life. NASA can't say whether there ever was life on Mars, but new evidence reinforces the idea that Mars was habitable. NASA's flagship Mars rover, Curiosity, has been combing the surface of Mars for signs of life for...