Geocheminar spring-2016

Planetesimal Swarms are not so Nice

Nice-type models have been a controversial element of the prevailing debate over solar system evolution. They incorporate a massive planetesimal swarm in the region between Uranus and Neptune, take many short-cuts in computing the gravitational interactions between the planetesimals themselves, as well as the major planets, and often change the physics that they employ in their computations as the simulations proceed. We shall show that this description for the planetesimals is fundamentally unstable, and that the outcomes presented for such models are, therefore, not valid.