Recent cryovolcanic activity at Occator crater on Ceres

A. Nathues, N. Schmedemann, G. Thangjam, J. H. Pasckert, K. Mengel, J. Castillo-Rogez, E. A. Cloutis, H. Hiesinger, M. Hoffmann, L. Le Corre, J. Y. Li, C. Pieters, C. A. Raymond, V. Reddy, O. Ruesch, D. A. Williams

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

NASA’s Dawn mission revealed a partially differentiated Ceres that has experienced cryovolcanic activity throughout its history up to the recent past. The Occator impact crater, which formed ~22 Myr ago, displays bright deposits (faculae) across its floor whose origins are still under debate: two competing hypotheses involve eruption of brines from the crust–mantle transition boundary (remnants of an ancient ocean) or alternatively from a shallow impact melt chamber. Here we report new constraints on the history of Occator that help in testing the hypotheses of its formation. We used high-resolution images of the Dawn Framing Camera obtained close to the end of the mission. We found a long-lasting and recent period of cryovolcanic activity, which started ≤9 Myr ago and lasted for several million years. Several resurfacing events, affecting the faculae and some (dark) solidified impact melt units, are shown to have occurred millions of years after crater formation and the dissipation of the impact-generated heat. These findings are indicative of a deep-seated brine source. Extensive volatile-driven emplacement of bright material occurred in the central floor, causing its subsidence due to mass loss at depth. Finally, a thick (extrusive) dome of bright material was raised in the central depression. The derived chronostratigraphy of Occator is consistent with a recently geologically active world, where salts play a major role in preserving liquid in a heat-starved body.

Original languageEnglish (US)
Pages (from-to)794-801
Number of pages8
JournalNature Astronomy
Volume4
Issue number8
DOIs
StatePublished - Aug 1 2020

ASJC Scopus subject areas

  • Astronomy and Astrophysics

Fingerprint Dive into the research topics of 'Recent cryovolcanic activity at Occator crater on Ceres'. Together they form a unique fingerprint.

Cite this