Marchi, S.S.MarchiErmakov, A. I.A. I.ErmakovRaymond, C. A.C. A.RaymondFu, R. R.R. R.FuO'Brien, D. P.D. P.O'BrienBland, M. T.M. T.BlandAmmannito, E.E.AmmannitoDE SANCTIS, MARIA CRISTINAMARIA CRISTINADE SANCTISBowling, T.T.BowlingSchenk, P.P.SchenkScully, J. E. C.J. E. C.ScullyBuczkowski, D. L.D. L.BuczkowskiWilliams, D. A.D. A.WilliamsHiesinger, H.H.HiesingerRussell, C. T.C. T.Russell2020-12-042020-12-0420162041-1723http://hdl.handle.net/20.500.12386/28719Asteroids 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.ELETTRONICOenArticle10.1038/ncomms122572-s2.0-84979529761000380197100001https://www.nature.com/articles/ncomms122572016NatCo...712257MFIS/05 - ASTRONOMIA E ASTROFISICA