Restricted three body problem is used to study the behavior of spacecraft, asteroids, and moons in systems like the Earth-Moon-Sun, Jupiter's moons etc. The present book deals with the problem of finding the existence and stability of the equilibrium points in the Elliptical restricted 3-body problem. It also helps in analyzing Lagrange points, which are positions in the orbital plane of the two massive bodies where the third body can maintain a stable position. Resonances play a critical role in understanding the long-term evolution of orbits in celestial mechanics. The linear and non-linear stability has been studied for 3rd and 4th order resonance.
