A low-density ocean inside Titan inferred from Cassini data

Journal article (2024)

Authors

A.C.H. Goossens NASA Goddard Space Flight Center
B.G. van Noort Center for Research and Exploration in Space Science and Technology, Student, Southeastern Universities Research Association
Alfonso Mateo Student
E. Mazarico NASA Goddard Space Flight Center
W. van der Wal Planetary Exploration - Aerospace Engineering
Research Group
Planetary Exploration (Aerospace Engineering) (TU Delft)
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Published Date

2024

Language

English

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Faculty

Aerospace Engineering

Department

Space Engineering

Research Group

Planetary Exploration

Abstract

The Cassini mission has provided measurements of the gravity of several moons of Saturn as well as an estimate of the tidal response, which is expressed as the degree 2 Love number k2 of its largest moon, Titan. The first estimates of Titan’s Love number were larger than pre-Cassini expectations. Interior modelling suggested it may be explained with a dense ocean, but the interpretation remains unclear. We analysed Cassini tracking data to determine Titan’s gravity field and its Love number. Our gravity results are consistent with earlier studies, but we find a lower Love number for Titan of k2 = 0.375 ± 0.06. This lower value follows from an elaborate investigation of the tidal effects. We show that a dense ocean is not implied by the obtained Love number; instead, a water or ammonia ocean is more probable. A lower density ocean can increase the likeliness of contact between the silicate core and ocean, which can leach minerals into the ocean and could promote its habitability.