Würzburg 2018 – scientific programme
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EP: Fachverband Extraterrestrische Physik
EP 2: Planets and small Objects
EP 2.3: Talk
Tuesday, March 20, 2018, 11:45–12:00, BSZ - Pabel HS
Are there features with impact origin on 67P/Churyumov-Gerasimenko? — •Jakob Deller1, Carsten Güttler1, Cecilia Tubiana1, Holger Sierks1, and the OSIRIS team2 — 1Max Planck Institute for Solar System Research (Justus-von-Liebig-Weg 3, D-37077 Göttingen) — 2MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Comet 67P/Churyumov-Gerasimenko shows a large variety of circular structures such as pits, elevated roundish features in Imhotep, and even a single occurrence of a plausible fresh impact crater. Analyzing images of the OSIRIS camera gives a set of detailed characteristics of these features. Using the iSALE code, simulations of impact experiments into a cometary analog material have been performed to investigate the plausibility of an impact origin of these features.
Two types of impacts are modelled: impact processes with rocky impactors and impact velocities varying from ~100 m/s to 7.5 m/s as typical for impacts during the late stage of 76P/Churyumov-Gerasimenko in the inner solar system, and slow (v_imp < 30m/s) impacts by impactors of the same material as the comet body as typical for accretion processes during the formation of the comet.
It is shown, that only the apparent fresh impact crater can directly be linked to impact processes. The prominent pit structures can as well as the elevated circular features found in the Imhotep region can in principle be explained by fast, rocky impactors in the late stage of the comets evolution, but additional erosional processes are needed to explain all observed characteristics of these features.