• Introduction
    • Lunar Prospector


      Lunar Prospector

      Lunar Prospector was designed to answer long-standing questions about the Moon’s resources, structure, and origins. Prospector mapped the Moon’s surface composition and looked for possible deposits of polar ice. It also measured magnetic and gravity fields and studied outgassing events. The mission had a dramatic ending – it intentionally impacted a crater near the lunar South Pole, in hopes that water vapor from suspected ice deposits would be released and a plume would be detectable from Earth.



      Mission Management

      Dr. Alan Binder
      Dr. Alan Binder
      Principal Investigator

      The Lunar Prospector mission was managed by NASA's Ames Research Center, Moffett Field, CA. Dr. Alan Binder of the Lunar Research Institute, Gilroy, CA, was the Principal Investigator. The mission was implemented by Lockheed Martin Missiles and Space, Sunnyvale, California.

  • Science Objectives
    • In 1992, a Lunar Exploration Science Working Group convened by NASA identified the most pressing, unanswered scientific riddles facing the lunar science community:

      How did the Earth-Moon system form?

      How did the Moon evolve?

      What constitutes the lunar atmosphere?

      What can the Moon tell us about the history of the Sun and other planets in the solar system?



      To address these priorities within the tight budget confines of the Discovery Program, mission designers selected the following science objectives to understand the origin, evolution and resources of the Moon:

      Search the lunar crust and atmosphere for potential resources, including minerals, water ice and certain gases

      Map the Moon’s gravitational and magnetic fields

      Learn more about the size and content of the Moon’s core




      Lunar Prospector being assembled.
      Lunar Prospector being assembled.













































  • Details
    • Lunar Prospector launched on a three-stage Athena II rocket from Cape Canaveral Air Force Station, Florida, on January 6, 1998. Five days later it successfully entered into a polar orbit 63 miles above the lunar surface to begin a 19-month global study of the Moon. The small, spin-stabilized spacecraft carried five scientific instruments but weighed only 650 pounds fully fueled - about a quarter as heavy as an average-sized car.



        Launch from Cape Canaveral, Florida.
        Launch from Cape Canaveral, Florida.








































  • Results
    • The data returned from Lunar Prospector enabled scientists to create the most complete and detailed maps to date of the gravity, magnetic properties and chemical composition of the entire lunar surface. While the Moon's magnetic field is relatively weak, Prospector detected large localized magnetic fields that create the two smallest magnetospheres in the solar system. The spacecraft also mapped the global distribution of major rock types and discovered signs of a tiny, iron-rich core.

      In March 1998, mission scientists announced tentative findings of the presence of water ice in shadowed craters near the Moon's south and north poles, based on reasonable scientific assumptions made from the levels of hydrogen detected. They estimated that as much as 200 million metric tons of water ice could exist at the poles. See Science Magazine, September 4, 1998, and the Lunar Prospector Spectrometers website for mission science results.

      The mission was scheduled to end in July 1999 when it would run out of fuel and randomly impact the lunar surface. Instead, in an attempt to find evidence of water ice, scientists came up with an innovative plan to direct the spacecraft to impact the Moon inside a permanently shadowed crater near the south pole. Scientists hoped the impact might free up water vapor and prove that water exists on the Moon.

      On July 31, 1999, the mission successfully ended when the spacecraft hit its intended target. Hundreds of amateur and professional astronomers watched for signs of the impact using everything from home-built telescopes to the world’s most powerful observatories, but no observable signature of water was produced. Learn more at the Lunar Prospector Impact Page.

      Overall, the mission exceeded expectations. With more than 6,800 lunar orbits, it provided a tremendous volume of valuable data that scientists will continue to analyze for years to come. For further information, visit the National Space Science Data Center, NASA's permanent archive for space science mission data.

      the south pole of the Moon
      picture of moonThis image shows significantly more hydrogen at the south pole of the Moon, signifying potential ice deposits. Credit: NASA Goddard Space Flight Center’s Scientific Visualization Studio.







  • Noteworthy
    • The Moon
        The Moon continues to be of great interest in our pursuit to understand the origin and evolution of the solar system. It is the most accessible and best studied rocky body beyond Earth. The Moon's surface geology preserves the record of nearly the entire 4.6 billion years of solar system history.

      The Apollo missions mapped only one-fourth of the lunar surface, around the Moon's equator. Lunar Prospector mapped the entire lunar surface and made the first direct measurement of ice at the lunar poles.

      In 2009, NASA searched for water on the Moon again, using the technique pioneered by Prospector. The Lunar Crater Observation and Sensing Satellite impacted into the permanently shadowed region of Cabeus crater near the Moon’s south pole on October 9, 2009. Data from LCROSS indicates that the mission successfully uncovered water.

      Lunar Prospector pioneered the development of a coordinated observation program. A similar but larger global observation effort took place on July 4, 2005 for the Deep Impact encounter with comet Tempel 1.