NASA announced that the James Webb Space Telescope (JWST) has discovered a previously unknown moon orbiting Uranus, raising the planet's tally of known natural satellites to 29.
The tiny moon, designated S/2025 U1, measures about 10 kilometers in diameter. Its small size and faint brightness are believed to have prevented its detection by earlier missions, including Voyager 2, which made its historic flyby of Uranus in 1986. The object was first detected in February through long-exposure observations using Webb's Near-Infrared Camera (NIRCam).
According to NASA, the new moon orbits Uranus at an estimated distance of 56,000 kilometers, nestled between the paths of the moons Ophelia and Bianca. Its nearly circular orbit along Uranus's equatorial plane offers researchers valuable insight into the planet's intricate system of rings and satellites.
The discovery was made by a team led by Maryame El Moutamid of the Southwest Research Institute in Texas, working in collaboration with NASA scientists. The group credited JWST's powerful imaging capabilities with enabling the detection of such a small and delicate object, one that had eluded previous ground-based and space telescopes.
NASA described the find as a significant step in expanding our understanding of Uranus and its complex environment. The discovery highlights Webb's ability to detect faint and distant objects in the solar system, providing a new window into planetary dynamics.
