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.

Uranus has 28 known moons in its orbit, but thanks to the James Webb Space Telescope, scientists believe they just uncovered a 29th moon.

Over millions of years, Uranus’s inner moons may have collided and spread out into rings. As the material in the rings diffused, they moved farther away from the planet. Eventually, that material can start to accumulate, recycling itself back into a moon.