CONSERT constrains the internal structure of 67P at a few-metre size scale

Valérie Ciarletti (1) , Alain Herique (2) , Jérémie Lasue (3) , Anny Chantal Levasseur-Regourd (1) , Dirk Plettemeier (4) , Florentin Lemonnier (1) , Christophe Guiffaut (5) , Pierre Pasquero (2) , Wlodek Kofman (2)

1 PLANETO - LATMOS
2 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
3 IRAP - Institut de recherche en astrophysique et planétologie
4 TU Dresden - Technische Universität Dresden = Dresden University of Technology
5 XLIM-SRF - Systèmes RF

The internal properties of cometary nuclei are the best clues to the size distribution and properties of the early planetesimals that formed the planets during the early solar system nebula processes. The CONSERT radar was designed to probe the interior of comet 67P/Churyumov-Gerasimenko with a wavelength of about 3 meters. It was successfully operated during the First Science Sequence of the Rosetta mission when the CONSERT’s wave propagated through part of the nucleus’ small lobe. The shape of the received signals provides some hints about the internal structure of the comet's small lobe. The limited broadening observed on the received pulses is compared to simulations performed on a series of non-homogeneous nucleus models to put constrains on the potential structures at the wavelength's scale. The study allows to exclude structures showing a permittivity contrast larger than 0.25 inside the sounded part of the nucleus at a few-metre size scale.

Keywords: scattering; radar; numerical simulation; comets; 67P/Churyumov–Gerasimenko

Domains: Sciences of the Universe [physics]

Valérie Ciarletti, Alain Herique, Jérémie Lasue, Anny Chantal Levasseur-Regourd, Dirk Plettemeier, et al.. CONSERT constrains the internal structure of 67P at a few-metre size scale. Monthly Notices of the Royal Astronomical Society, 2017, 469 (Suppl_2), pp.S805-S817. ⟨10.1093/mnras/stx3132⟩. ⟨insu-01689580⟩