NASA scientists have identified a previously unknown moon orbiting Uranus using the James Webb Space Telescope. The object, provisionally designated S/2025 U1, is estimated to be only about six miles (10 kilometres) across—roughly the length of 90 football fields—making it the smallest satellite yet found around the ice giant. Located roughly 35,000 miles (56,000 kilometres) from Uranus’s centre, the tiny body circles the planet on a near-circular path between the orbits of the moons Ophelia and Bianca. Its discovery raises the planet’s confirmed moon count to 29 and underscores the telescope’s ability to detect faint, inner satellites that escaped detection by earlier missions, including Voyager 2’s 1986 fly-by. Researchers led by Maryame El Moutamid of the Southwest Research Institute spotted the moon in ten 40-minute infrared exposures taken on 2 February 2025 with Webb’s NIRCam instrument. Team member Matthew Tiscareno of the SETI Institute said the densely packed inner moons and their interaction with Uranus’s rings hint at a chaotic evolutionary history and suggest additional, still-hidden moons may exist. The new satellite will receive an official name once approved by the International Astronomical Union.