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Predictions for impactor contamination on Ceres based on hypervelocity impact experiments
Author(s) -
Daly R. Terik,
Schultz Peter H.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl065601
Subject(s) - regolith , debris , hypervelocity , impact crater , projectile , astrobiology , geology , sublimation (psychology) , asteroid , snow , environmental science , geomorphology , materials science , physics , astronomy , psychology , oceanography , metallurgy , psychotherapist
New experiments predict that Ceres should be extensively contaminated with meteoritic debris derived from the asteroid belt. All types of impactors likely contribute to the contamination. Ceres may accrete debris more efficiently if it is ice‐rich because of enhanced projectile survival and retention in porous ice targets. Experiments indicate that if a silicate regolith lag protects subsurface ice, then some of the projectile should be injected into the regolith during high‐angle impacts, thereby hiding part of the projectile component from view. If impacts excavate ice, sublimation will gradually concentrate projectile relics into a surficial lag. In contrast, if the near‐surface lacks ice, then accreted meteoritic debris should be distributed throughout a vertically mixed regolith. High‐resolution images may reveal pristine projectile relics lining some crater floors. Moreover, we predict that the surface of Ceres is not exclusively endogenic and may be dominated by delivered exogenic debris.