The Lunar Prospector was one of the NASA Discovery Program missions. It was designed to perform a low polar orbit investigation of the Moon. This included mapping the surface composition and locating lunar resources, measuring magnetic and gravity fields, and studying outgassing events. The data from this mission, which carried only scientific instruments, complemented the image data from the Clementine mission, which carried mostly cameras. The information gathered improved the understanding of the origin, evolution, and current state of the Moon.