how do current models explain the origin of the kuiper belt? what role does planetary migration play? how do current models explain the origin of the kuiper belt? what role does planetary migration play? the kuiper belt is composed of ice-rich planetesimals that formed outside the orbit of neptune. during the planetary migration processes, the kuiper belt lost the majority of its original mass and orbital resonances with jovian planets gave the belt the form it has today. the kuiper belt is composed of metal-rich planetesimals that formed inside the orbit of jupiter. during the planetary migration processes, the kuiper belt gained the most of its present mass and orbital resonances with jovian planets gave the belt the form it has today. the kuiper belt is composed of ice-rich planetesimals that formed outside the orbit of neptune. during the planetary migration processes, the kuiper belt gained the most of its present mass and orbital resonances with jovian planets gave the belt the form it has today. the kuiper belt is composed of metal-rich planetesimals that formed inside the orbit of jupiter. during the planetary migration processes, the kuiper belt lost the majority of its original mass and orbital resonances with jovian planets gave the belt the form it has today.