Some models[1] suggest that Neptune and Uranus formed closer to the sun, and then migrated to their current orbits later (explanations vary between Jupiter and

Some models[1] suggest that Neptune and Uranus formed closer to the sun, and then migrated to their current orbits later (explanations vary between Jupiter and Saturn pulling them out, or some extrasolar mass). 1: https://en.wikipedia.org/wiki/Neptune#Formation_and_migration https://en.wikipedia.org/wiki/Neptune#Formation_and_migratio...