SpaceX rocket on collision course with moon

A discarded SpaceX Falcon 9 upper stage will unintentionally slam into the moon on Wednesday, carving a crater and sending debris that scientists are eager to observe. Space tracking expert Bill Gray predicts an impact at 5,400 mph near Einstein Crater, visible from parts of the Americas. The crash, packing the energy of three tons of TNT, highlights the growing hazards of space junk as lunar missions increase.