Radiation sputtering of hydrocarbon ices at Europa-relevant temperatures

Salty ocean layer is envisioned under the thick icy shell of Europa. Often, geological activity brings subsurface materials on to the Europa’s water ice surface, like Saturn’s moon Enceladus. Jupitar’s high-energy radiation environment can alter the subsurface materials. Recent detection of CO2 on Europa enhanced interest to understand the possible generation of CO2 through radiolysis of organic material. Radiolysis by high-energy electrons or ions can sputter CO2 and organic fragments into Europa’s exosphere. In this study, the radiation sputtering of CO2 and organics fragments from hydrocarbon water ice mixtures is investigated at different Europa surface temperatures. This study shows that the sputtering of hydrocarbon water ice leads to the production of mostly CO2, CO, and fragmented hydrocarbons. The sputtering evolution of fragmented hydrocarbons immediately goes high and comes to a steady state, whereas CO2 and CO reach slowly towards maxima. Temperature-dependent sputtering yield is also explored, and it is found that at a higher Europa temperature, sputtering yield maximizes.