He was trying to solve the three body problem. Kepler followed by Newton, solved the two body problem, but the three body problem completely defied analysis. That is, can you come up with a mathematical description that exactly describes the motions of three gravitationally attracted bodies? Well the answer now, seems to be no. A three-body or higher system seems to be chaotic. In other words, if you try to describe the motion of three bodies all gravitationally attracted to each other, and then you try to describe a very slightly different system, after time the two systems will be completely different. However, LaGrange found that there were five positions where a third body could orbit along with two other bodies predictably.
Our Sacramento L5 Society is named for the Lagrange Point EML5. Just like the illustration above for the Sun Earth Lagrange Points the Earth and the Moon have a similar geometry of points where it’s easier to track the revolution of the moon in a space craft.
