Restored Apollo Lunar Surface Magnetometer Data, Release 1

Restored Apollo Lunar Surface Magnetometer Data

Release 1

Peter Chi

Department of Earth Planetary and Space Sciences, University of California Los Angeles, and

Moon Economics Institute

This Apollo Lunar Surface Magnetometer (LSM) dataset is derived from the Apollo correction tapes generated by the instrument team and archived at the NASA Space Science Data Coordinated Archive (NSSDCA). The original LSM data stored on these magnetic tapes consist of 0.3-second vector magnetic field samples, with timestamps recorded in 36-bit words. The author undertook a restoration effort to decode these data and convert them into ASCII listings.

The variables in this dataset are presented in the following order:

1. Year
2. Month
3. Day
4. Hour
5. Minute
6. Second
7. Bx in nanotesla (nT)
8. By in nanotesla (nT)
9. Bz in nanotesla (nT)

The magnetic field components are expressed in the Apollo Lunar Surface Experiments Package (ALSEP) coordinate system, where:

• The X-axis points radially outward from the ALSEP (toward the zenith).
• The Z-axis lies in the ALSEP meridian plane, pointing northward.
• The Y-axis lies in the equatorial plane, completing the right-handed system.

Occasional errors in reading the magnetic tapes and translating them into valid values, based on the known data format, have contributed to some of the gaps or spikes in the time series data.

The locations of the Apollo LSM’s, in selenographic coordinates, are as follows:

• AP 12 LSM Latitude = -3.0098 deg Longitude = -23.4249 deg
• AP 15 LSM Latitude = 26.13406 deg Longitude = 3.62991 deg
• AP 16 LSM Latitude = -8.9759 deg Longitude = 15.4986 deg

Palmer Dyal served as the Principal Investigator for the Apollo Lunar Surface Magnetometers. David R. Williams provided the NSSDC archive of the LSM data to the author. The following article references the use of this restored Apollo LSM dataset:

Chi, P. J., C. T. Russell, H. Y. Wei, and W. M. Farrell (2013), Observations of narrowband ion cyclotron waves on the surface of the Moon in the terrestrial magnetotail, Planetary and Space Science, 89, 21-28, doi:10.1016/j.pss.2013.08.020.

For any questions regarding this restored Apollo LSM dataset, please contact Peter Chi at pchi@epss.ucla.edu.