Restricted 3-body problem predicted Trojan asteroids

The restricted 3-body problem simplifies the issue to one body that is massless, and all three are in a plane. The two bodies with mass orbit each other. In the rotating frame of reference where the two finite-mass bodies are stationary, there are 5 points on the plane where the third body can remain motionless. Depending on the ratio of the masses, these points are either unstable or stable to small perturbations. The sun and Jupiter fit the ratio where two of the points are stable. The existence of the Trojan asteroids was predicted 134 years before they were actually found.

https://www.britannica.com/science/celestial-mechanics-physics/The-three-body-problem