Research Unit “Debris Disks in Planetary Systems”

"Chury" as soft as a bath foam

When ESA's Rosetta lander Philae touched down on the nucleus of comet 67P/Churyumov-Gerasimenko ("Chury") in 2014, it bounced off the surface several times before it came to its final rest. Researchers from ESA and several international institutions reconstructed Philae's penultimate contact (called TD2) with the surface of 67P. In a paper published in Nature on 28th October 2020 they describe their meticulous search for TD2 and their findings about Philae's interactions with the surface material of 67P. Members of the Research Unit 2285 have analyzed the imprint that Philae left on the "boulder" it hit and came to the conclusion that the material is not at all "boulder"-like, but softer than ash. A maximum compressive strength of 12 Pa was determined, which can only be explained by 67P consisting of macroscopic granular matter with very weak cohesion. This is consistent with earlier findings and helps the researchers of the Research Unit 2285 to refine their collision models for macroscopic bodies in debris disks.
(Animation credits: European Space Agency)


O'Rourke et al. (2020), Nature 586, 697−701
Press release of TU Braunschweig
Press release of ESA
News report of Nature


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