Lagrange point

Syllable breakdown

Dictionary meaning

one of five gravitational equilibrium positions in a two-body orbital system such as the Earth-Sun or Earth-Moon system where a small object can theoretically remain stationary relative to both large bodies because the gravitational and centrifugal forces acting on it exactly balance; named after Italian-French mathematician Joseph-Louis Lagrange who calculated their existence in 1772; the five points are designated L1 through L5; L1, L2, and L3 lie along the line connecting the two large bodies and are unstable equilibria, while L4 and L5 are stable and collect dust and asteroids known as trojans; the James Webb Space Telescope orbits at the Earth-Sun L2 point, approximately 1.5 million kilometres from Earth, where it can maintain a stable cold environment shielded from the Sun while observing deep space