Jupiter L5: a Sun–Jupiter Lagrange point
The Sun–Jupiter L5 point lies about 60° behind Jupiter in its orbit. This is a reference location in space, with Trojan asteroids gathering nearby.
Jupiter L5 is a Lagrange point of the Sun–Jupiter system, about 60° behind Jupiter in its orbit. The marker identifies this reference location and nearby Trojan region. It has no physical surface or planetary shell.
What is a Lagrange point?
In an idealized model of two large bodies orbiting their common center of mass, five locations allow a suitably moving small object to retain a fixed relative configuration. These Lagrange points, L1 through L5, arise from gravity and orbital motion, not the absence of gravity.
L1, L2, and L3 lie on the Sun–Jupiter line. L4 is about 60° ahead and L5 about 60° behind, each forming an equilateral triangle with Sun and planet.
L1–L3 tend to amplify small departures. L4 and L5 are relatively stable in the ideal model, supporting nearby oscillating orbits. Real perturbations mean stability is not eternal rest at one point.
Why do asteroids remain nearby?
Viewed in a frame rotating with Jupiter, suitable trajectories inhabit comparatively stable regions for long periods. Trojans are spread across space, not packed into a gravity-free point.
Which body do they orbit?
Trojans orbit the Sun with roughly Jupiter’s period, rather than orbiting Jupiter as moons. Real orbits tilt and oscillate; the diagram’s regular circles simply explain the relationship.
What will Lucy visit?
The L5 population contains the Patroclus–Menoetius binary, scheduled for a 2033 flyby. Its similarly sized partners may preserve clues to early paired assembly.
Why no diameter?
L5 is a mathematical reference location, and its surrounding population has no sharp edge. A physical diameter would be misleading. Selecting it helps place nearby asteroids in context.
