For small bodies that lack an intrinsic atmosphere, the harsh space environment – often consisting of energetic photons and charged particles - can alter and damage the surfaces of icy and rocky bodies alike. Such alterations induced by these ‘space weathering’ agents can be readily observed either remotely, through spectral changes, or in situ by orbiting spacecraft which are able to directly measure neutral or charged species released (or sputtered) into the exospheres of these bodies. Here, we present some recent work from the EPICS laboratory at GeorgiaTech on our recent investigations on the absolute yields of positively-charged species released during electron-stimulated desorption (ESD) experiments on water ice, methanol ice, and Apollo lunar samples investigated using time-of-flight (ToF) spectrometry. The yields of all species observed are presented as a function of electron energy (12.5 eV - 2 keV). At higher energies, clusters dominate the total yield removed, while several species of interest to planetary science are observed directly (including H3+, O2+, H2O2+, O2+); although we discuss a potential for generation of some species ex situ. The surface morphology and underlying substrate are shown to play a key role on the observed yields. The experiments on icy surfaces directly simulate the interactions of the magnetospheres of giant planets with their surrounding icy satellites and therefore have implications for upcoming missions such as JUICE (e.g., Europa, Ganymede & Callisto).

Results from recent experiments on electron-stimulated desorption from icy & rocky surfaces

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.