6. Differential Nongravitational Forces in the Motions of the Split Comets

The new model, which has recently been proposed for the motions of fragments of the split comets, is critically examined through a comparison with the traditional approach. It is concluded that the new model, based on the premise that the rate of separation of any two fragments of a split comet is determined primarily by the differential nongravitational forces in their motions, is preferable in many a respect to the traditional hypothesis, built on the assumption that significant impulses are exerted on the fragments at the time of splitting. The new model appears to have interesting implications for the physics of cometary splitting, suggesting that the breakup mechanism may essentially be non-violent or of a low degree of violence, and for estimates of cometary masses.