The 2009 Fermi Symposium

Fermi First-year Observations of the Albedo Gamma-ray Emission from the Moon

Nicola Giglietto

Abstract:

We report the detection of the lunar albedo gamma-ray emission during the first year of Fermi-LAT observations. Such emission is produced by cosmic ray nuclei interacting with the lunar surface. Thanks to the solar minimum conditions and the reduced effects of heliospheric modulation, the lunar albedo flux was at its maximum due to the increased flux of Galactic cosmic rays hitting the lunar surface. Fermi-LAT instrument has a superior sensitivity, angular resolution, and observes the whole sky every two orbits. It is the only gamma-ray mission capable of detecting the lunar emission with high confidence and to monitor it over the full 24th solar cycle. We also report the status of a search of the albedo gamma-ray emission from major planets and asteroid populations in the ecliptic plane.