Geomorphological evidence for ground ice on dwarf planet Ceres

Nature Geoscience
By: , and 

Links

Abstract

Five decades of observations of Ceres suggest that the dwarf planet has a composition similar to carbonaceous meteorites and may have an ice-rich outer shell protected by a silicate layer. NASA’s Dawn spacecraft has detected ubiquitous clays, carbonates and other products of aqueous alteration across the surface of Ceres, but surprisingly it has directly observed water ice in only a few areas. Here we use Dawn Framing Camera observations to analyse lobate morphologies on Ceres’ surface and we infer the presence of ice in the upper few kilometres of Ceres. We identify three distinct lobate morphologies that we interpret as surface flows: thick tongue-shaped, furrowed flows on steep slopes; thin, spatulate flows on shallow slopes; and cuspate sheeted flows that appear fluidized. The shapes and aspect ratios of these flows are different from those of dry landslides—including those on ice-poor Vesta—but are morphologically similar to ice-rich flows on other bodies, indicating the involvement of ice. Based on the geomorphology and poleward increase in prevalence of these flows, we suggest that the shallow subsurface of Ceres is comprised of mixtures of silicates and ice, and that ice is most abundant near the poles.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Geomorphological evidence for ground ice on dwarf planet Ceres
Series title Nature Geoscience
DOI 10.1038/ngeo2936
Volume 10
Year Published 2017
Language English
Publisher Nature
Contributing office(s) Astrogeology Science Center
Description 6 p.
First page 338
Last page 343