The three-body problem is one of the oldest problems in physics: It concerns the motions of systems of three bodies—like the sun, Earth, and the moon—and how their orbits change and evolve due to their mutual gravity. The three-body problem has been a focus of scientific inquiry ever since Newton.
When one massive object comes close to another, their relative motion follows a trajectory dictated by their mutual gravitational attraction, but as they move along and change their positions along their trajectories, the forces between them, which depend on their mutual positions, also change, which, in turn, affects their trajectory. For two bodies (e.g., the Earth moving around the sun without the influence of other bodies), the orbit of the Earth would continue to follow a specific curve (an ellipse), which can be accurately described…
