A RADIO SCIENCE EXPERIMENT TO STUDY THE INTERIOR OF THE URANIAN MOONS.

Abstract

The five largest moons of Uranus, as well as Uranus itself, have mostly been studied through ground-based observations [e.g., 1]. Only Voyager 2 provided in situ measurements that significantly enhanced our understanding of the system [2,3]. As a ten-year launch window approaches, the scientific community has agreed on the importance of prioritizing a robotic mission to Uranus, proposing it as the next NASA flagship-class mission [4]. In response to this, NASA is reviewing the Uranus Orbiter and Probe (UOP) mission concept [5]. The concept was evaluated by the most recent Planetary Science and Astrobiology Decadal Survey [4] as a low-risk, relatively low-cost, and high-reward mission. Upon arrival, the mission would deploy an atmospheric probe, settle into orbit around Uranus for 4.5 Earth years, and conduct flybys of several moons. A Radio Science (RS) experiment that includes multiple satellite flybys (in addition to the orbital phase around Uranus) can provide valuable information about the interior properties, formation, evolution, and potential habitability of the planetary bodies in the Uranian system, as previously demonstrated [6-7]. An RS experiment can answer key science questions regarding the internal structure and rock-to-ice ratios of the large satellites of Uranus, and help identifying significant internal heat sources or possible oceans.