Astronomers using the James Webb Space Telescope have found an unknown moon orbiting Uranus, bringing the planet’s total to 29 — and more likely remain undiscovered.

In the space close to the icy planet, outside its ephemeral rings, JWST snapped a tiny object that no one had ever seen before, not even in data from the Voyager 2 probe that flew past Uranus at a close distance in 1986.