The solar system contains many, extremely diversified, small bodies : over 3 500 comets and 15 000 asteroids have been registered to date.
The comets were created 4,5 billion years ago, before the planets. Together with the other small bodies, they are considered to be the most primitive members of the solar system, and are veritable « fossil » remnants of the primordial material from which it was made.
Cosmic « Rosetta stones », these objects are for our understanding of the World what the hieroglyphics were for Egyptologists: : echoes of the past.
The Rosetta mission will try to unveil the processes relating to the origin of the solar system, and to study how cometary and interplanetary material is related. To do this, it will study in situ the cometary nucleus, its structure, its environment, and how they evolve as a function of the comet’s heliocentric distance.
The probe carries twenty scientific instruments (eleven on board the orbiter and nine on the lander Philae) to carry out the most detialed yet exploration of a comet.
Source : Agenda astronomique 2014, Institut de mécanique céleste et de calcul des éphémérides de l’Observatoire de Paris, EDP sciences