Science Objectives For A Mission Concept To Enceladus: The Astrobiology

The Cassini-Huygens mission provided unprecedented information regarding Enceladus’ surface and interior, including the discovery of a subsurface ocean and strong evidence for waterrock interactions, which could provide the physical and chemical conditions conducive to habitability as we know it.

Cassini identified tectonic fractures at Enceladus’ south pole from which a cryovolcanic plume is sourced, which very likely contains material from the subsurface ocean. Access to this subsurface ocean via the analysis of plume material presents a unique and exciting opportunity to examine the interior chemistry of an icy moon, including any potential biosignatures, without the cost and risk associated with landed mission architectures.

Astrobiology eXploration at Enceladus is a New Frontiers (NF) class mission (based on the NF-4 AO) designed to examine the surface and interior of Enceladus in an effort to examine its potential for past or present life. Here, we present the science objectives of the AXE mission, their rationale, and the necessary measurements required for their science closure.

Science Objectives: The primary goal of the AXE mission is twofold: (1) to search for biosignatures within the plume of Enceladus, and (2) to contextualize potential biosignatures through an assessment of Enceladus’s habitability in space and time.

These goals are expressed through four science objectives (Fig. 2), described in detail below, which are achieved using an instrument payload consisting of a high-resolution telescopic camera and a mass spectrometer, with gravity science conducted using a high gain antenna.

For more detail regarding the science mission profile, mission architecture, and spacecraft trajectory, please see the adjacent mission implementation abstract.

Full abstract, 53rd Lunar and Planetary Science Conference (2022)

Astrobiology