Model of a Giant Impact on Saturn

PARISI, M. G.; BRUNINI, A.

Vicosa, Brasil

Conferencia; XI Coloquio Brasilero de Dinamica Orbital; 2002

The origin of the obliquities of the giant planets is one of the fundamental questions of cosmogony. Large stochastic impacts are believed to play a key role during the last stage of the formation of the planets and have been considered as a possible explanation to account for the planetary spin obliquities. We assume that the obliquity of Saturn (26.7 degrees) is due to a giant off-center impact with another protoplanet. We obtain that the impactor mass required to tilt Saturn is 6-7.2  Earth masses. This range of masses set a constraint for the mass of the planetary embryos in the outer Solar System. In order to get dynamical constraints, we study the possible scenarios taking into account the mechanisms of satellite formation and the physical and dynamical characteristics of the Saturnian moons.