Publication Date:
2022-05-26
Description:
Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Icarus 189: 72-82, doi:10.1016/j.icarus.2007.01.010.
Description:
Recent observations of the south pole of Saturn’s moon Enceladus by the Cassini
spacecraft have revealed an active world, powered by internal heat. In this paper, we
propose that localized subsurface melting on Enceladus has produced an internal south
polar sea. Evidence for this localized sea comes from the shape of Enceladus, which
does not match a differentiated body at its current orbital position. We show that melting
induced by the observed heat flow at the south pole produces a large enough pit to match
the shape of Enceladus with a differentiated rock and ice interior. Numerical modeling of
melting and ice flow shows that the sea produced beneath the south pole is stable against
inflow of ductile ice from its surroundings for the duration of the heating. The shape
modification due to melting also produces a negative degree-two gravity anomaly, which
can reorient the spin axis of Enceladus in order to place the sea at the pole.
Keywords:
Enceladus
;
Satellites
;
Shapes
;
Interiors
;
Geophysics
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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