Introduction to the special issue: The formation and evolution of Ceres’ Occator crater

Abstract

Ceres, the largest body in the asteroid belt, was explored from orbit for the first time by the Dawn mission. The ∼92 km-diameter Occator crater contains bright regions, or faculae, which are one of the most remarkable discoveries of Dawn's exploration of Ceres. A pit within the center of the crater contains both the Cerealia Facula and a central dome. The Vinalia Faculae are located in the eastern crater floor. Occator's faculae are composed mostly of sodium carbonate and their single scattering albedo is the highest of any material on Ceres’ surface. The faculae do not occur in other impact craters on Ceres and Occator's extensive interior lobate materials are unusual. Understanding the driving forces behind the formation of Occator crater and its faculae has the potential to lead us to a new understanding of the processes and conditions in Ceres’ past, and to possibly provide constraints about the present-day internal state. In this special issue we present a variety of investigations, which use Dawn data, theoretical modeling and laboratory experiments to investigate Occator crater and its faculae. The results of these investigations are summarized and synthesized in the final paper of this collection. Herein we introduce Ceres and the Dawn mission and summarize the geophysical, geological, mineralogical and geochemical properties of Ceres as derived from Dawn data. We also discuss the regional setting of Occator crater and introduce Occator crater itself.