In 1989, the Voyager 2 mission discovered six new moons orbiting Neptune, including five tiny ones that orbit just outside the planet’s main rings. Because of their small sizes and locations, these satellites have been difficult to study from Earth. Now, using NASA’s James Webb Space Telescope (JWST), a team of Caltech researchers has observed Neptune’s rings and three of those moons—Larissa, Galatea and Proteus—and found that their composition is unique among outer solar system bodies.