Presentation #103.05 in the session Unmeltable Me, verse 1: From the Sky to the Lab.
Planetary surfaces not protected by a sufficient atmosphere experience particle bombardment which can affect the surface’s chemical evolution. For the icy moons orbiting Jupiter and Saturn, particle irradiation can take the form of micrometeorites, electrons, and ions from the solar wind or the host planet’s magnetic environment. When an irradiating particle hits a planetary surface, some amount of the impacted surface material can be ejected, which is known as sputtering. Sputtering depends on multiple factors including the impacted surface’s composition and temperature as well as the impactor’s type and energy. Electron irradiation of icy surfaces is not as well researched as ion irradiation, and previous electron irradiation experiments have determined the total yield of sputtered material without discerning between sputtered compositional components (Meier and Loeffler, 2020). Recent work looked at the O2 sputtering yields from the irradiation of amorphous solid water at intervals between 14 and 125 K with 0.5 keV electrons (Davis et al., 2021) and found that the global O2 production on Europa from electron irradiation was larger than O2 production from all ionic irradiation components combined. We are expanding the studies done by Davis et al. (2021) to determine O2 sputtering yields resulting from various impacting electron energies over a range of temperatures relevant to Jovian and Saturnian satellites between 40 and 125 K. This presentation will highlight some of our most recent laboratory results.