NASA’s James Webb Space Telescope has found a previously unknown moon orbiting Uranus. NASA announced the discovery on Tuesday, adding that the moon was first spotted on Feb. 2. Scientists estimate that the newly discovered moon is about six miles in diameter.

NASA scientists at the Southwest Research Institute discovered a 29th moon orbiting Uranus while using infrared detection through the James Webb Space Telescope. The discovery was made on Feb. 2, but NASA officials did not announce the discovery until Tuesday in a news release.

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.