Figure 2
From: Active moon: evidences from Chandrayaan-1 and the proposed Indian missions
Lunar atmosphere-hydrosphere-surface exchange processes are schematically shown. The radiation present in the lunar environment, besides sunlight, consists of solar wind, solar flares, galactic cosmic rays, X rays and proton induced X rays. Both sinks (gravitational escape, photoionisation loss, chemical loss and condensation of particles at the cold traps) and sources (thermal desorption, sputtering, material brought in by meteorites, comets and asteroids, and internal sources and gases released by bubbles formed in lunar grains) in the environment are shown.