Radiation-induced near-surface atmospheres of Europa and Titan

Murthy S. Gudipati (1) , Bryana L. Henderson (1) , Benjamin Fleury (2) , Nathalie Carrasco (3, 2) , Nathalie Rivas (1) , Isabelle Couturier-Tamburelli (4) , Véronique Vuitton (5)

1 JPL - Jet Propulsion Laboratory
2 PLANETO - LATMOS
3 IUF - Institut universitaire de France
4 Spectrométries et Dynamique Moléculaires
5 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

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.

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]

Murthy S. Gudipati, Bryana L. Henderson, Benjamin Fleury, Nathalie Carrasco, Nathalie Rivas, et al.. Radiation-induced near-surface atmospheres of Europa and Titan. European Planetary Science Congress 2015, Sep 2015, Nantes, France. pp.EPSC2015-768-2. ⟨insu-01208355⟩