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PDS Geosciences Node, Washington University in St. Louis
Geosciences Node Data
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Lunar Prospector Level 1 Spectrometer Data

Lunar Prospector gamma ray, neutron, and alpha particle spectrometer Level 1 data sets and associated documentation are available from the PDS Geosciences Node. These data products and documentation have been prepared by the Lunar Prospector Spectrometer Team at the Los Alamos National Laboratory. The Level 1 products typically are expressed in counts rather than abundances or fluxes. Color-coded maps derived from these data are also available for browsing. Higher level products will be posted as they become available.

These spectrometer data products integrate data collected between January 16, 1998 and July 31, 1999.

IMPORTANT: The data on this page are special products that may be of interest to the geoscience community. They do not represent a PDS peer-reviewed archive. Please report any other anomalies in the data or documentation to


  1. README File

    A README file for this data release as submitted by the Lunar Prospector Spectrometer Team.

  2. Data Product Description

    Three documents (in Adobe Acrobat format) that describe the file formats for the spectrometer data products.

  3. Instrument Description

    A Spectrometer Team document (in Adobe Acrobat format) that provides a technical description of the Lunar Prospector spectrometers.

  4. Auxiliary Information

    A file that lists times of solar energetic particle events. Gamma ray and neutron spectrometer data are omitted from the data products for these time periods. The file also lists times of gain changes for the gamma ray spectrometer and other significant mission events.


The Lunar Prospector spectrometer data are stored in a Common Data Format (CDF) file structure. Your browser's "SAVE LINK AS" function can be used to download these data files. A procedure that can import the spectrometer data into IDL has been provided by the LP Spectrometer Team.

  1. Integrated Gamma Ray Spectra (Each file is 14.7 Mbytes)

    Files containing integrated gamma ray spectra for the entire Moon. The individual gamma ray spectra have been integrated over a given time period and binned into 5 x 5 degree cells. Each integrated spectra has 512 channels. Values are in units of counts per 32-seconds (The instrument takes 32 seconds to acquire a spectrum).

  2. Thorium and Potassium Count Rates (Each file is 71 kbytes)

    Files containing thorium and potassium count rates derived from gamma ray spectra. The data have been binned into 5 x 5 degree cells that cover the entire Moon. The thorium count rate is the sum of counts from within an energy band (2.4 to 2.8 MeV) around the thorium gamma ray line of 2.6 MeV. The potassium count rate is the sum of counts from within an energy band (1.3 to 1.5 MeV) around the potassium gamma ray line of 1.46 MeV. Values are in units of counts per 32-seconds.

  3. Thermal and Epithermal Neutron Count Rates (Each file is 71 kbytes)

    Files containing thermal and epithermal neutron count rates derived from neutron spectra. The data have been binned into 5 x 5 degree cells that cover the entire Moon. The thermal neutron count rate is the difference in the count rate between the HeCd and HeSn detectors. The epithermal neutron count rate is the count rate of the HeCd detector. Values are in units of counts per 32-seconds.

  4. Alpha Particle Spectrometer Time Series Data (File size varies)

    The Alpha Particle Spectrometer (APS) data are organized by time. Each file contains approximately one day of data. Each record includes time of day, latitude, longitude, height of spacecraft above the surface, APS face number, look angle, and energy level. The APS files are accessible by anonymous FTP at this URL: 


These maps were produced by the Lunar Prospector Spectrometer Team. 

  1. Thorium Map

  2. Potassium Map

  3. Thermal Neutron Map

  4. Epithermal Neutron Map

The LP Level 1 spectrometer data are provided by the PDS Geosciences Node for use by the planetary community and the interested public. Copies of the data will also be available through the National Space Science Data Center (NSSDC).


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Curator: Susan Slavney
NASA Official: Raymond E. Arvidson
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