The missing large impact craters on Ceres #MMPMID27459197
Marchi S; Ermakov AI; Raymond CA; Fu RR; O'Brien DP; Bland MT; Ammannito E; De Sanctis MC; Bowling T; Schenk P; Scully JEC; Buczkowski DL; Williams DA; Hiesinger H; Russell CT
Nat Commun 2016[]; 7 (ä): ä PMID27459197show ga
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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Nat+Commun 2016 ; 7 (ä): ä
