Lagrangian points ラグランジュ・ポイント
宇宙活動

Five geometric positions in outer space where an object can theoretically maintain a stable orbit due to the gravitational forces of two larger objects, namely planet-moon systems and star-planet systems. Calculated by the Italian-French mathematician Joseph Louis Lagrange in 1772 and designated L1, L2, L3, L4, and L5, they are said to be the ideal locations for setting up large-scale man-made installations near Earth. The first 3 points are not considered stable enough for a space colony, so all valuable real estate in space is centered around points L4 and L5. Beyond Coast is located in an orbit around L5, as it was discovered in 1968 through a mathematical calculation that a colony could not be placed directly at L4 or L5, but would need to be in an orbit around it.