Abstract

Bio-signatures from Enceladus' Geysers using transits from 2023

Philip Judge (High Altitude Observatory)

Europa and Enceladus are two objects in the solar system harboring subsurface liquid water. Enceladus is a prolific emitter of fountains of matter from the subsurface, Europa has one confirmed emission event. The purpose of this paper is to argue for the search for spectral biosignatures using transits of Enceladus across the disk of Saturn. From the Earth's neighborhood, transits will begin again in 2023. The technique is analogous to the transits of planets and their atmospheres across the Sun and stars, except one uses reflected and thermal light emitted by the planetary disk as the source. JWST is ideally suited to such measurements, having the capability to observe from visible to infrared wavelengths without detrimental effects of seeing. It high angular resolution is also necessary. Differential spectroscopy of the transiting satellite can achieve enormous signal-to-noise ratios permitting us to look for biogenic signatures in the absorption spectra of the emitted plumes. Some transits of Europa across Jupiter's disk would also seem worthwhile before 2023.

Mode of presentation: poster