Uranus has a new, hidden moon, James Webb Space Telescope reveals

Just when you think we've found all the moons around the planets in our own solar system, the 29th moon orbiting Uranus has been discovered. There's actually so much we don't know about our own solar system.  

(Image:  Uranus in an image captured by the James Webb Space Telescope. (Image credit: NASA, ESA, CSA, STScI)

 Uranus has a new, hidden moon, James Webb Space Telescope reveals

Ben Turner, Live Science, August 20, 2025

Uranus' 29th moon was hidden inside the planet's dark inner rings, new observations from the James Webb Space Telescope reveal.

The moon, for now dubbed S/2025 U1, is just 6 miles (10 kilometers) in diameter, which is why it was invisible to other telescopes and the Voyager 2 spacecraft when it made its 1986 flyby of the icy planet.

Now, the James Webb Space Telescope's (JWST) Near-Infrared Camera (NIRCam) has detected glints of sunlight in a series of ten 40-minute long-exposure images of Uranus, which revealed the elusive moon's presence. The discovery hints that much more remains hidden around Uranus, the astronomers who found the moon say.

(Image: Uranus and some of its moons, with S/2025 U1 circled. (Image credit: NASA, ESA, CSA, STScI, M. El Moutamid (SwRI), M. Hedman (University of Idaho))

"No other planet has as many small inner moons as Uranus, and their complex inter-relationships with the rings hint at a chaotic history that blurs the boundary between a ring system and a system of moons," Matthew Tiscareno, a senior research scientist at the SETI Institute in Mountain View, California, and a member of the research team, said in a statement. "Moreover, the new moon is smaller and much fainter than the smallest of the previously known inner moons, making it likely that even more complexity remains to be discovered."

First spotted in 1781 by the German-British astronomer Frederick William Herschel, Uranus is the seventh planet from our sun and orbits it at a distance of 1.8 billion miles (2.9 billion km), nearly 20 times farther than Earth, according to NASA.