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The missing large impact craters on Ceres

S. Marchi·A. Ermakov·C.A. Raymond·R.R. Fu·D.P. O’Brien·Michael T. Bland·E. Ammannito·De Sanctis·Tim Bowling·P. Schenk·J.E.C. Scully·D.L. Buczkowski·D.A. Williams·H. Hiesinger·C.T. Russell
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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.

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S. Marchi, A. Ermakov, C.A. Raymond, R.R. Fu, D.P. O’Brien, Michael T. Bland, E. Ammannito, De Sanctis, Tim Bowling, P. Schenk, J.E.C. Scully, D.L. Buczkowski, D.A. Williams, H. Hiesinger, C.T. Russell. 2016-07-26. The missing large impact craters on Ceres. https://doi.org/10.1038/ncomms12257

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