Ring current H atom precipitation on the outer planets

Abstract

Voyager has revealed the presence of an extended neutral gas corona on Saturn and Uranus. This observed feature leads to the occurrence of charge-exchange loss of energetic charged particles of the ring current: causing important energetic and dynamic effects in the upper atmospheres of these planets through precipitation. This paper explores the importance of this process in producing H Lyα, Hα, Hβ, and H₂ band emissions on the outer planets. This mechanism is found to be an important source of optically thin H Lyα emissions from the outer planets.