A study of the past dynamics of comet 67P/Churyumov-Gerasimenko with fast Lyapunov indicators

¹ Università degli Studi di Padova, Dipartimento di Matematica, via Trieste, 63 – 35121 Padova Italy
e-mail: guzzo@math.unipd.it
² Université de Nice Sophia Antipolis, CNRS UMR 7293, Observatoire de la Côte d’Azur, Bv. de l’Observatoire, C.S. 34229, 06304 Nice Cedex 4, France
e-mail: elena.lega@oca.eu

Received: 12 February 2015
Accepted: 13 April 2015

Abstract

Comet 67P/Churyumov-Gerasimenko is the target of the Rosetta mission. On the basis of backward numerical integrations of a large set of simulated comets whose initial conditions were obtained from small variations of the orbital parameters of comet 67P, and using the analysis of suitable chaos indicators, we detect the phase-space structure of the past close encounters of the comet with Jupiter. On the basis of these computations we find that the probability that the comet could have been injected into the inner solar system from distances larger than 100 AU from the Sun in the past 150 000 years is about 60 percent.