Desorption Processes in Planetary Science

Abstract

Surfaces of materials in the solar system and the interstellar media, not protected by atmospheres, can be exposed to a variety of energetic particle radiations: cosmic rays, solar particles and photons, and plasma particles trapped in planetary magnetospheres. Of considerable interest in planetary science is the exchange of atoms and molecules between the gaseous and condensed phases. Hence our ability to describe desorption from surfaces, stimulated by electronic energy deposition in a variety of materials, is a limiting factor in interpreting many remote sensing and spacecraft data. For instance, line/band spectra can often be obtained on atoms/molecules in the gas phase in the interstellar medium or near remote objects in the solar system like Io (a satellite of Jupiter) or the planet Mercury. Further, the nature of the radiation environment may be known and, indeed, the local plasma may be ionized species desorbed from the surface. As reflectance spectra of the surface or, in the interstellar media, light extinction curves due to the presence of grains, give much less or, often, no information on the surface composition, a description of the desorption processes can be critical in placing constraints on the composition. Recently a number of review articles have appeared which summarize aspects of the importance of electronically induced desorption and sputtering in planetary science[1–6]. Therefore, I briefly list some areas of interest, giving reference to these article and some other primary or secondary references.KeywordsSolar SystemInterstellar MediumDesorption ProcessLocal PlasmaOuter Solar SystemThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.