The varied sources of faculae-forming brines in Ceres' Occator crater emplaced via hydrothermal brine effusion

J E C Scully; P M Schenk; J C Castillo-Rogez; D L Buczkowski; D A Williams; J H Pasckert; K D Duarte; V N Romero; L C Quick; M M Sori; M E Landis; C A Raymond; A Neesemann; B E Schmidt; H G Sizemore; C T Russell

doi:10.1038/s41467-020-15973-8

The varied sources of faculae-forming brines in Ceres' Occator crater emplaced via hydrothermal brine effusion

Nat Commun. 2020 Aug 10;11(1):3680. doi: 10.1038/s41467-020-15973-8.

Authors

J E C Scully¹, P M Schenk², J C Castillo-Rogez³, D L Buczkowski⁴, D A Williams⁵, J H Pasckert⁶, K D Duarte⁷, V N Romero⁷, L C Quick⁸, M M Sori⁹, M E Landis¹⁰, C A Raymond³, A Neesemann¹¹, B E Schmidt⁷, H G Sizemore¹², C T Russell¹³

Affiliations

¹ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. [email protected].
² Lunar and Planetary Institute, Houston, TX, USA.
³ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
⁴ Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA.
⁵ School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA.
⁶ Institute für Planetologie, University of Münster, Münster, Germany.
⁷ Georgia Institute of Technology, Atlanta, GA, USA.
⁸ NASA Goddard Space Flight Center, Greenbelt, MD, USA.
⁹ Lunar and Planetary Laboratory, Tucson, AZ, USA.
¹⁰ Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, USA.
¹¹ Free University of Berlin, 14195, Berlin, Germany.
¹² Planetary Science Institute, Tucson, AZ, USA.
¹³ University of California, Los Angeles, CA, USA.

Abstract

Before acquiring highest-resolution data of Ceres, questions remained about the emplacement mechanism and source of Occator crater's bright faculae. Here we report that brine effusion emplaced the faculae in a brine-limited, impact-induced hydrothermal system. Impact-derived fracturing enabled brines to reach the surface. The central faculae, Cerealia and Pasola Facula, postdate the central pit, and were primarily sourced from an impact-induced melt chamber, with some contribution from a deeper, pre-existing brine reservoir. Vinalia Faculae, in the crater floor, were sourced from the laterally extensive deep reservoir only. Vinalia Faculae are comparatively thinner and display greater ballistic emplacement than the central faculae because the deep reservoir brines took a longer path to the surface and contained more gas than the shallower impact-induced melt chamber brines. Impact-derived fractures providing conduits, and mixing of impact-induced melt with deeper endogenic brines, could also allow oceanic material to reach the surfaces of other large icy bodies.