Astronomy Any of five points in the orbital plane of two bodies, one of which is much larger than the other, at which a third, even smaller body will remain in gravitational equilibrium. Bodies located at Lagrangian points appear stationary with respect to the larger two bodies. Also called Lagrange point .
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Lagrangian point. (n.d.). Retrieved January 15th, 2019, from https://www.yourdictionary.com/lagrangian-point
A point in space where a small body with negligible mass under the gravitational influence of two large bodies will remain at rest relative to the larger ones. In a system consisting of two large bodies (such as the Sun-Earth system or the Moon-Earth system),
there are five Lagrangian points (L1 through L5). Knowledge of these points is useful in deciding where to position orbiting bodies.