Kuiper binary formation

It has been observed that binary Kuiper Belt Objects (KBOs) exist contrary to theoretical expectations. Their creation presents problems to most current theoretical models. However, the inclusion of a third body (for example, one of the outer planets) may provide the conditions necessary for the formation of these objects. The presence of a third massive body not only helps clear the primordial Kuiper Belt but can also result in long lived binary KBOs. The gravitational interaction between the KBOs and the third body causes one of four effects; scattering into the Oort cloud, collisions with the growing protoplanets, formation of binary pairs, or creation of a single KBO. Additionally, the initial location of the progenitors of the KBOs can also have a significant effect on binary formation.