Prospects of Passive Radio Detection of a Subsurface Ocean on Europa with a Lander

TL;DR

This paper evaluates the potential of a lander-based passive radio system to detect subsurface oceans on Europa, highlighting its advantages over orbiter-based methods and estimating detection depths based on ice properties.

Contribution

It introduces a passive radio detection technique for landers, demonstrating improved sensitivity and broader operational bandwidth compared to previous orbiter studies.

Findings

Detects subsurface ocean up to 6.9 km in high-loss ice

Detects subsurface ocean up to 69 km in pure ice

Offers a low-resource, effective detection method

Abstract

We estimate the sensitivity of a lander-based instrument for the passive radio detection of a subsurface ocean beneath the ice shell of Europa, expected to be between 3~km - 30~km thick, using Jupiter's decametric radiation. A passive technique was previously studied for an orbiter. Using passive detection in a lander platform provides a point measurement with significant improvements due to largely reduced losses from surface roughness effects, longer integration times, and diminished dispersion due to ionospheric effects allowing operation at lower frequencies and a wider band. A passive sounder on-board a lander provides a low resource instrument sensitive to subsurface ocean at Europa up to depths of 6.9~km for high loss ice (16 dB/km two-way attenuation rate) and 69~km for pure ice (1.6 dB/km).