Scientists look to crack mystery: Maybe ice?
                                
                                
                                    (Newser) -
                                    Heavy rocks seems to move by themselves in one part of California's Death Valley, their means of locomotion a scientific mystery,  LiveScience  reports. Though no one has ever seen them move, rocks the size of large soda bottles criss-cross the surface of Racetrack Playa, leaving trails. "You don't expect...