Properties of the 67P/Churyumov-Gerasimenko interior revealed by CONSERT radar

Wlodek Kofman (1) , Alain Herique (1) , Yves Barbin (2) , Jean-Pierre Barriot (3) , Valérie Ciarletti (4) , Stephen Clifford (5) , Peter Edenhofer (6) , Charles Elachi (7) , Christelle Eyraud (8) , Jean-Pierre Goutail (9) , Essam Heggy (10, 7, 11) , Laurent Jorda (12) , Jérémie Lasue (13) , Anny Chantal Levasseur-Regourd (4) , Erling Nielsen (14) , Pierre Pasquero (1) , Frank Preusker (15) , Pascal Puget (1) , Dirk Plettemeier (16) , Yves Rogez (1) , Holger Sierks (14) , Christoph Statz (16) , Hakan Svedhem (17) , Iwan Williams (18) , Sonia Zine (1) , Jakob van Zyl (7)

1 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
2 MIO - Institut méditerranéen d'océanologie
3 GePaSUD - Géopôle du Pacifique Sud
4 PLANETO - LATMOS
5 LPI - Lunar and Planetary Institute [Houston]
6 Department of Electrical Engineering Information Technology [Bochum]
7 JPL - Jet Propulsion Laboratory
8 HIPE - HIPE
9 LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales
10 USC - University of Southern California
11 USC Viterbi School of Engineering
12 LAM - Laboratoire d'Astrophysique de Marseille
13 IRAP - Institut de recherche en astrophysique et planétologie
14 MPS - Max-Planck-Institut für Sonnensystemforschung
15 DLR Institute of Planetary Research
16 TU Dresden - Technische Universität Dresden = Dresden University of Technology
17 ESTEC - European Space Research and Technology Centre
18 QMUL - Queen Mary University of London

The Philae lander provides a unique opportunity to investigate the internal structure of a comet nucleus, providing information about its formation and evolution in the early solar system. We present Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) measurements of the interior of Comet 67P/Churyumov-Gerasimenko. From the propagation time and form of the signals, the upper part of the “head” of 67P is fairly homogeneous on a spatial scale of tens of meters. CONSERT also reduced the size of the uncertainty of Philae’s final landing site down to approximately 21 by 34 square meters. The average permittivity is about 1.27, suggesting that this region has a volumetric dust/ice ratio of 0.4 to 2.6 and a porosity of 75 to 85%. The dust component may be comparable to that of carbonaceous chondrites.

Domains: Earth and Planetary Astrophysics [astro-ph.EP]

Wlodek Kofman, Alain Herique, Yves Barbin, Jean-Pierre Barriot, Valérie Ciarletti, et al.. Properties of the 67P/Churyumov-Gerasimenko interior revealed by CONSERT radar. Science, 2015, 349 (6247), pp.aab0639. ⟨10.1126/science.aab0639⟩. ⟨insu-01182590⟩