Scientists: Photos show evidence of water on Mars

New photographs from space suggest that water occasionally flows on the frigid surface of Mars, raising the tantalizing possibility that the Red Planet is hospitable to life, scientists reported Wednesday. The new images, taken by NASA's Mars Global Surveyor before it lost contact with Earth, do not actually show flowing water. Rather, they show changes in craters that provide the strongest evidence yet that water coursed through them as recently as several years ago, and is perhaps doing so even now. "This is a squirting gun for water on Mars," said Kenneth Edgett, a scientist at San Diego-based Malin Space Science Systems, which operates a camera on the Global Surveyor.