Electrostatic charging properties of Apollo 17 lunar dust

We report on our experimental studies of the electrostatic charging properties of an Apollo 17 soil sample and two lunar simulants, Minnesota Lunar Simulant (MLS-1) and Johnson Space Center (JSC-1). We have measured their charge after exposing individual grains to a beam of fast electrons with energies in the range of 20 less than or equal to E less than or equal to 90 eV. Our measurements indicate that the secondary electron emission yield of the Apollo 17 sample is intermediate between MLS-1 and JSC-1, closer to that of MLS-1.