Radiation-induced near-surface atmospheres of Europa and Titan
Résumé
We will discuss and compare photochemical processes on Europa and Titan, focusing on the near- surface and lower-atmospheric organic composition on both of these moons. Europa's surface receives high doses of radiation that can easily oxidize organics in the presence of water-ice. Titan's atmosphere is depleted of oxygen, but enriched with organic molecules, including condensed aerosols.
In this contribution we will focus on photochemistry caused by longer wavelength UV-VIS photons (>250 nm) photons that can pass through Titan’s atmosphere to the haze region (~100 km) and onto the surface of Titan [1, 2] and electron-induced processes of organics on Europa's surface, leading to the formation of Europa's tenuous atmosphere [3-6]. We then compare the role of organics on both of these astrobiologically-important icy bodies in our solar system.