Question 1

True or false: The James Webb Space Telescope orbits the Sun-Earth L2 Lagrange point.

Accepted Answer

True. JWST is stationed at Sun-Earth L2, about 1.5 million km from Earth, where it stays aligned with Earth's orbit and keeps its sunshield facing the Sun.

Question 2

True or false: The Trojan asteroids of Jupiter orbit at the planet's L4 and L5 Lagrange points.

Accepted Answer

True. Thousands of asteroids called Trojans share Jupiter's orbit, clustered around its stable L4 and L5 points, leading and trailing the planet by 60 degrees.

Question 3

True or false: A satellite at a Lagrange point can stay there without using any fuel at all.

Accepted Answer

False. Even at Lagrange points, satellites need small station-keeping thruster burns to stay precisely in place due to gravitational perturbations from other planets and solar radiation pressure.

Question 4

True or false: There are exactly five Lagrange points for any two-body system in space.

Accepted Answer

True. Joseph-Louis Lagrange discovered five equilibrium points (L1 through L5) in the circular restricted three-body problem. L4 and L5 are stable, L1-L3 are unstable.

Question 5

True or false: If you put a satellite at L1, it can always see both the Sun and the Earth simultaneously.

Accepted Answer

True. L1 is directly between the Sun and Earth, so a satellite there has an uninterrupted view of both. That's why solar observatories like SOHO use it.

Question 6

True or false: A spacecraft at the Earth-Sun L2 point is completely hidden from the Sun at all times.

Accepted Answer

False. L2 is behind Earth from the Sun, but Earth's shadow doesn't fully cover it. JWST uses a large sunshield to block sunlight, but it still gets some stray light.

Question 7

True or false: Lagrange points are only useful for science missions and have no military applications.

Accepted Answer

False. The US Space Force considers Lagrange points strategically important for future space-based assets, including potential surveillance or communications relays, though no weapons are placed there now.

Question 8

True or false: The Moon has its own Lagrange points with Earth that are completely empty.

Accepted Answer

False. Earth-Moon Lagrange points are real, but L4 and L5 contain faint dust clouds called Kordylewski clouds, not complete emptiness. They're very sparse and hard to detect.

Lagrange Point Trivia Questions