Dione's leading/trailing dichotomy at 2.2 cm

Léa Bonnefoy (1, 2) , Alice Le Gall (1, 3) , Marie Azevedo (4) , Emmanuel Lellouch (2) , Cédric Leyrat (2) , Michael A. Janssen (5)

1 PLANETO - LATMOS
2 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics
3 IUF - Institut universitaire de France
4 LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales
5 JPL - Jet Propulsion Laboratory

The surface of Dione, Saturn’s fourth-largest moon, is affected by a variety of processes, both exogenic and endogenic, although the satellite does not seem to be active today [e.g., 1]. Like its neighboring mid-sized icy airless satellites Tethys and Rhea, it exhibits a leading/trailing dichotomy, observed at UV to IR wavelengths [e.g., 2]. This dichotomy has also been reported at 2.2 cm wavelengths, in the unique resolved observation acquired by the Cassini Radar on Dione [3, Fig. 1b]. The leading hemisphere is more radar-bright than the trailing hemisphere, implying greater water ice purity on the leading side. This asymmetry may be caused by the deposition of E-ring material on the leading side, and/or by contamination by a non-icy material on the trailing side. Herein, we examine Cassini radiometry observations of Dione.

Domaines: Planète et Univers [physics]

Léa Bonnefoy, Alice Le Gall, Marie Azevedo, Emmanuel Lellouch, Cédric Leyrat, et al.. Dione's leading/trailing dichotomy at 2.2 cm. Europlanet Science Congress EPSC 2020, Sep 2020, Virtual Meeting, Germany. pp.EPSC2020-329. ⟨insu-02943256⟩