Kuiper belt: formation and evolution

This chapter reviews accretion models for Kuiper belt objects (KBOs), discussing in particular the compatibility of the observed properties of the KBO population with the streaming instability paradigm. Then it discusses how the dynamical structure of the KBO population, including the formation of its five subcomponents (cold, hot, resonant, scattered, and fossilized), can be quantitatively understood in the framework of the giant planet instability. We also establish the connections between the KBO population and the Trojans of Jupiter and Neptune, the irregular satellites of all giant planets, the Oort cloud and the D-type main belt asteroids. Finally, we discuss the collisional evolution of the KBO population, arguing that the current size-frequency distribution below 100 km in size has been achieved as a collisional equilibrium in a few tens of Myr inside the original massive Trans-Neptunian disk, possibly with the exception of the cold population subcomponent.