Focusing on a certain type of asteroids in the Kuiper Belt and Oort Cloud can help better explain planetary migration.
Gravitational instability is one way to describe the formation of the Kuiper Belt.
The Kuiper Belt formed during the instability of the orbits of Uranus and Neptune.
Kuiper Belt Objects originated in the inner solar system.
Grand Tack Model accurately describes the formation of the Oort Cloud.
The Nice Model does not accurately describe the formation of the Oort Cloud.
The analysis of the recently discovered rocky comet C/2014 S3 in the Oort Cloud is evidence that ejections of rocky material to either the Kuiper Belt or the Oort Cloud is possible.
During the Sun’s migration to its current location, it may have collected comets and rocky material from other stars.
The Galactic Tides felt by our solar system may be one of the reasons the Oort Cloud is a sphere and not a ring like the Kuiper Belt, and compliments the Nice Model.
While the Sun was moving away from the center of our galaxy, it might have lost some comets to the galactic gravitational pull of the Milky Way Galaxy, meaning that the planetary migration had no effect on the formation of the Kuiper Belt or the Oort Cloud.