Can the Nice Model Save the Earth?
(Brasser et al. 2009)
Recall that the Kuiper belt shows that the outer planets migrated.
But look what happens to the terrestrial planets when the migration is smooth:
The terrestrial planets become unstable!!!!!
Happens because the planets cross
If the giant planets encounter one another they can jump over the resonances.
This can save the terrestrial planets.
But only works ~6% of the time.
This is a problem and an active area of research.