A Nice Story:
I am going to try to convince you that:
- The 4 giant planets formed within 15AU or 20AU of the Sun.
- Beyond them was a massive disk that extended to ~30AU.
- The 4 giant planets slowly spread due to leakage from this disk.
- Jupiter and Saturn crossed the 1:2 mean motion resonance at 700Myr
- Uranus and Neptune went unstable and scattered into the disk.
- Producing the Trojans, Kuiper belt, irregular satellites, Primitive main belt asteroids, and lunar Late Heavy Bombardment (LHB).
- Uranus and Neptune evolve onto current orbits due to interactions with the disk.
And everyone lived happy ever after.
5AU
10AU
15AU
20AU
30AU