Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

67P/Churyumov–Gerasimenko

  • Hervé CottinEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_5042-3

Keywords

Comet ROSETTA 

Synonyms

67P

Definition

Comet 67P/Churyumov–Gerasimenko is the target of the ESA ROSETTA mission. This comet was selected because its orbit allowed its exploration by the European spacecraft for a launch scheduled in 2004 and an encounter in 2014. It was also of particular interest since it is thought that the comet has not a long history in the inner Solar System and therefore could contain primitive material kept at low temperature and far from the Sun since the formation of the Solar System.

Overview

Comet 67P/Churyumov–Gerasimenko is the target of the ESA ROSETTA mission. ROSETTA has reached the comet in August 2014 and delivered on the nucleus a lander called PHILAE on November 12, 2014, after a global mapping of the surface in order to choose the best landing site. The comet was discovered by Klim Ivanovich Churyumov and Svetlana Ivanovna Gerasimenko in September 1969. Its current orbital period is 6.44 years, with an aphelion at 5.7 AU and a perihelion at 1.24 AU. Observations of the nucleus with ROSETTA have revealed a stunning unexpected irregular shape with two lobes. This could be the sign that the comet is made of two distinct objects that came into contact or that the primary nucleus was asymmetrically eroded. Comet 67P nucleus (Fig. 1) is about 4.1 × 3.3 × 1.8 km in size for the larger lobe and 2.6 × 2.3 × 1.8 km for the smaller one. Its mass is 1.0 × 1013 kg and density about 0.5 g.cm3. It rotates in about 12.4 h.
Fig. 1

Picture of the nucleus of comet 67P/Churyumov–Gerasimenko seen from the ROSETTA spacecraft on September 19, 2014, from a distance of about 30 km. The two lobes can be seen as well as the irregular terrains made of pits, cliffs, boulders, and rather smooth areas (Credit: ESA/Rosetta/NAVCAM)

It has been calculated that before 1840, the comet perihelion was about 4 AU and that successive dynamical interactions with Jupiter progressively shifted it to its current position.

Comet Churyumov–Gerasimenko is the first cometary nucleus so closely scrutinized by a spacecraft, for such a long period of time (about 2 years) and on which an automated module has landed.

See Also

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Laboratoire Interuniversitaire des Systèmes AtmosphériquesUniversité Paris Est-CréteilCréteil CedexFrance