The James Webb Space Telescope orbits the Sun near Sun-Earth Lagrange point 2 (L2), approximately 1.5 million kilometers (1 million miles) from Earth. L2 is one of five Sun-Earth Lagrange points, positions in space where the gravitational pull of the Sun and Earth combine such that small objects in that region have the same orbital period (length of year) as Earth. This makes it possible for Webb to remain in constant communication with Earth.
Webb is not located at L2, but instead orbits L2, completing one circuit every 168 days. This "halo orbit" around L2 is highly elliptical and is roughly perpendicular to its orbital path around the Sun. The distance between Webb and L2 varies between about 250,000 and 830,000 kilometers (150,000 - 500,000 miles). Because of this complex orbit, Webb's precise distance from Earth varies over time.
Sizes and distances in this illustration are not to scale. The actual distance between the Sun and Earth is about 100 times the distance between Earth and L2. The distance between Earth and L1 is almost the same as between Earth and L2. L2 is about four times farther from Earth than the Moon. The long diameter (major axis) of the halo orbit around L2 is around the same as the distance between Earth and L2.
Graphic and caption updated: October, 2022
Credits
Image
NASA, STScI
