S20A0111abst
S20A0111
Many icy bodies in our solar system, Jupiter’s moon Europa and Saturn’s moon Enceladus, are likely to contain oceans underneath their icy shell, and could harbor conditions suitable for life beyond Earth. Cassini spacecraft has found various non-water volatiles, hydrocarbons and organic molecules in water plume spewing from Enceladus. Also several plumes at the southern limb of Europa have been just confirmed several times, and only water molecules have been identified through transit observations in ultraviolet with the Hubble Space Telescope (HST). Here, we propose to measure the time variation of the plume activities over its full orbital phase and to constrain an upper mass limit of 100,000 kg at 3.5 sigma, corresponding to one-fiftieth of the previous plume activities observed by HST in 2016. This allows us to investigate whether or not the plume activities occur temporally. We also propose an approach for the first detection of non-water volatiles and organic molecules from the Europa plumes and the remnant atmosphere attributed to the plumes through high-dispersion infrared spectroscopic observations. This chemical characterization provides a clue for understanding whether or not the subsurface liquid ocean is reducing like the Earth’s ancient ocean.
This document was translated from LATEX by HEVEA.