Exploring Earth's Moon
|The Moon||Upcoming Visits||Past Visitors||Water & Ice|
|Gravity Maps||Molten Heart||Retroreflectors||Lava Flows|
|Love Numbers||Founder Ashes||Lunar Distance||Dung Beetle|
|Lunar Hotel||Moon Resources||Other Solar System Moons|
Lunar Prospector gathered data at an altitude of 62 miles above the Moon in 1998-1999. It moved into an orbit as low as six miles above the lunar surface so its instruments can collect close-up data. The probe's gamma ray spectrometer will measure the Moon's surface composition and structure.
Before Lunar Prospector, tracking data from old-time NASA Lunar Orbiter and Apollo missions of the 1960s had suggested the lunar gravity field is not uniform. It was effected by variations in the concentrations of mass on the Moon caused by lava which had flowed into the Moon's huge craters eons ago. Maps of those mass concentrations only covered the equatorial region of the nearside of the Moon. Lunar Prospector improved that situation dramatically.
Telemetry data from Lunar Prospector was used to produce a gravity map of both the near and far sides of the Moon. Researchers found two new mass concentrations on the Moon's nearside. This first-ever engineering-quality gravity map of the entire Moon will make future lunar missions safe and fuel-efficient.