A photo from Cassini shows sunlight reflecting from a giant lake of methane on the northern half of Saturn's moon Titan. (CNN) -- NASA scientists revealed Friday a first-of-its-kind image from space showing reflecting sunlight from a lake on Saturn's largest moon, Titan. It's the first visual "smoking gun" evidence of liquid on the northern hemisphere of the moon, scientists said, and the first-ever photo from another world showing a "specular reflection" -- which is reflection from a liquid surface. Jaumann said he was surprised when he first saw the photos transmitting from Cassini, orbiting Saturn about a billion...