SOHO SWAN Lyα Models Supporting LRO LAMP: 2008–2023

Abstract

The Lunar Reconnaissance Orbiter Lyman-Alpha Mapping Project (LAMP) has been mapping the Moon since its launch in 2009. Faint ultraviolet illumination of the lunar dark side includes light from stars and from hydrogen Ly α emissions, mostly attributed to sunlight scattered by hydrogen atoms near the Sun with a smaller contribution from the whole Galaxy. Models of the lunar illumination by time-dependent Ly α photons have allowed the LAMP team to map polar shadowed craters suspected of harboring water ice and other volatiles. This paper describes the model that provides daily all-sky Ly α maps tuned by comparisons with all-sky Ly α maps from the SOlar and Heliospheric Observatory Solar Wind ANisotropy Experiment stationed at the Sun–Earth L1 point.

Keywords

• Heliosphere