Well, this is pretty cool:
Thanks to extensive computer simulations, the researchers have calculated that the current asymmetry [in the counts of Trojan asteroids] could only have occurred if Jupiter was formed four times further out in the solar system and subsequently migrated to its current position. During its journey towards the sun, Jupiter’s own gravity then drew in more Trojans in front of it than behind it.
Jupiter’s unknown journey revealed
Image credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill