People are silhouetted against a rising full moon as they ride an attraction at Worlds of Fun amusement park Thursday, July 30, 2015, in Kansas City, Mo. When the full moon appears at 6:43 a.m. EDT (1043 GMT) in the U.S. Friday, it will become the second full moon of July. Geoff Chester of the U.S. Naval Observatory said the traditional definition of a blue moon is two full moons in a month. (AP Photo/Charlie Riedel), APTOPIX