The shape and structure of small asteroids as a result of sub-catastrophic collisions
Publisher DOI
Abstract
The overall shape, internal structure and surface morphology of small bodies such as asteroids and comets aredetermined to a large degree by the last global-scale impact or disruption event. Depending on the specific energy,impacts lead to a large spectrum of outcomes. Sub-catastrophic disruptions take place in an energy range betweencratering impacts and catastrophic disruptions. Although less energetic than catastrophic events, they can stillsignificantly alter the overall shape and structure of the target body. This has been demonstrated recently in thecase of bi-lobe cometary nuclei (Jutzi and Benz, 2017). Here we present results of a subsequent study on theshapes of asteroids resulting from such collisions. Sizes ranging from a few hundred meters to a few kilometers areconsidered.We show that impacts on elongated rotating asteroids frequently lead to the formation of contact binaries. Ourresults confirm that this mechanism is robust and works for a large range of asteroid sizes and impact velocities.Scaling-laws for the prediction of the size and velocity dependent specific energies required for successful bi-lobeformation are presented. Based on these scaling laws, the expected frequency of such sub-catastrophic impacts iscalculated and is compared to the one of catastrophic disruptions, which require much higher specific energiesand are more rare.Our analysis suggest that the shapes and structures of a large fraction of small asteroids as observed today maybe the result of the last major sub-catastrophic impact
Date Issued
2019
Publication Type
Article
Subject(s)
Language(s)
en
Additional Credits
Journal
Planetary and space science
Publisher
Elsevier
ISSN
0032-0633
Access(Rights)
restricted