title: The missing large impact craters on Ceres.
abstract: Asteroids provide fundamental clues to the formation and evolution of planetesimals. Collisional models based on the depletion of the primordial main belt of asteroids predict 10-15 craters >400 km should have formed on Ceres, the largest object between Mars and Jupiter, over the last 4.55 Gyr. Likewise, an extrapolation from the asteroid Vesta would require at least 6-7 such basins. However, Ceres' surface appears devoid of impact craters >∼280 km. Here, we show a significant depletion of cerean craters down to 100-150 km in diameter. The overall scarcity of recognizable large craters is incompatible with collisional models, even in the case of a late implantation of Ceres in the main belt, a possibility raised by the presence of ammoniated phyllosilicates. Our results indicate that a significant population of large craters has been obliterated, implying that long-wavelength topography viscously relaxed or that Ceres experienced protracted widespread resurfacing.
authors.affiliation: Southwest Research Institute, Boulder, Colorado 80305, USA.
authors.forename: S
authors.initials: S
authors.lastname: Marchi
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A I
authors.initials: AI
authors.lastname: Ermakov
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Raymond
authors.affiliation: Lamont-Doherty Earth Observatory, Columbia University, New York, New York 10968, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Fu
authors.affiliation: Planetary Science Institute, Tucson, Arizona 85719, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: O'Brien
authors.affiliation: USGS Astrogeology Science Center, Flagstaff, Arizona 86001, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Bland
authors.affiliation: Department of Earth and Space Sciences, University of California, Los Angeles, California 90095, USA.
authors.forename: E
authors.initials: E
authors.lastname: Ammannito
authors.affiliation: Istituto di Astrofisica e Planetologia Spaziali, INAF, Roma 00133, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: De Sanctis
authors.affiliation: Department of Geophysical Sciences, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: T
authors.initials: T
authors.lastname: Bowling
authors.forename: P
authors.initials: P
authors.lastname: Schenk
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
authors.forename: J E C
authors.initials: JE
authors.lastname: Scully
authors.affiliation: John Hopkins Applied Physics Laboratory, Laurel, Maryland 20723, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Buczkowski
authors.affiliation: School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Williams
authors.affiliation: Institut für Planetologie, Westfälische Wilhelms-Universität, Münster 48149, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Hiesinger
authors.affiliation: Department of Earth and Space Sciences, University of California, Los Angeles, California 90095, USA.
authors.forename: C T
authors.initials: CT
authors.lastname: Russell