Philae Landing on Comet 67P/Churyumov Gerasimenko, planned chirality measurements and ideas for the future

Abstract

Philae is a comet Lander, part of the ESA Rosetta Mission to comet 67P/Churyumov-Gerasimenko. After a ten year cruise through the solar system it successfully landed on the nucleus of the comet on November 12th, 2014. Philae´s payload consists of ten scientific instruments [1], including COSAC, an evolved gas analyser with the capability to differentiate chiral molecules [2,3]. After the touchdown of Philae, the anchoring harpoons, which were expected to fix the lander to ground, did not work, Philae bounced in the low gravity environment, and only came to rest after a 2 hours “hop” in an unforeseen area on the comet surface [4]. Although, the scientific instruments, including cameras, mass spectrometers (including the one of COSAC [5]), a magnetometer and a radar instrument could be operated, and fascinating, unprecedented scientific results have been obtained, it was not possible to collect a sample of the surface material and no gas chromatography measurement could be performed. Thus, the measurement of the chirality of molecules on comets, is still to be done in the future. The paper will describe the Philae mission and the attempts to measure chiral molecules with COSAC, but also suggest future measurements with returned samples from the primitive asteroids (162173)Ryugu and (101955)Bennu with the spacecraft Hayabusa 2 (JAXA) and OSIRIS-REx (NASA), respectively. Both will reach their targets in 2018. Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae Lander is provided by a consortium led by DLR, MPS, CNES and ASI with additional contributions from Hungary, UK, Finland, Ireland and Austria.