Lagrange Points

Parking spots in space

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Lagrange points let small objects keep pace with two orbiting bodies.
• L1 and L2 sit about $R(m/3M)^{1/3}$ from the smaller body: 1.5 million km for Earth.
• L4 and L5 are stable and collect Trojan asteroids.

Steps

1. Balance points
2. Why can L2 work?
3. Find L2
4. The cube-root rule
5. Talking to L2
6. Trojans