Astronomers Discover New Moon Orbiting Uranus Using James Webb Space Telescope

A team of researchers led by the Southwest Research Institute has identified a previously unknown moon orbiting the planet Uranus. The discovery was made using data collected by the James Webb Space Telescope during a series of observations conducted in early 2025. This new addition brings the total number of known moons orbiting the seventh planet from the Sun to 29. Dr. Maryame El Moutamid, a lead scientist in the Solar System Science and Exploration Division at the Southwest Research Institute, headed the survey team. The discovery occurred after the team analyzed 10 long-exposure images captured by the telescope's Near-Infrared Camera on February 2, 2025. The object has been given the provisional designation S/2025 U 1. Scientists estimate the new moon is approximately six miles, or 10 kilometers, in diameter. This size makes it the smallest satellite discovered around Uranus to date. Its small stature explains why it remained hidden from previous missions, including the Voyager 2 flyby in 1986, which lacked the sensitivity to detect such a faint object. The moon is located within the planet's equatorial plane, positioned between the orbits of two other known moons, Ophelia and Bianca. It sits roughly 35,000 miles, or 56,250 kilometers, from the center of Uranus. This region is situated at the edge of the planet's inner ring system. Uranus is known for having a diverse collection of satellites, many of which are named after characters from the works of William Shakespeare and Alexander Pope. The research team is currently considering potential names for the new discovery that align with this long-standing tradition. The process of selecting a formal name involves careful consideration of the cultural history associated with the Uranian system. The James Webb Space Telescope continues to provide unprecedented views of the outer solar system. By utilizing advanced infrared technology, the observatory can peer through the glare of giant planets to find smaller, cooler objects that were previously invisible. This capability is helping astronomers refine their understanding of how planetary systems form and evolve over time. This discovery highlights the ongoing utility of the telescope's guest observer program. By allowing researchers to target specific regions of space, the program enables the identification of small-scale features that might otherwise be overlooked. Each new moon provides additional data points for scientists studying the gravitational dynamics of the Uranian environment. Future observations may help researchers determine the composition and orbital stability of S/2025 U 1. Understanding the characteristics of such small moons is essential for building a complete picture of the debris and satellites surrounding ice giants. These findings contribute to the broader goal of mapping the architecture of our solar system. The team's work underscores the importance of international collaboration in space exploration. The James Webb Space Telescope is a joint project involving NASA, the European Space Agency, and the Canadian Space Agency. These organizations work together to operate the observatory and process the vast amounts of data it returns to Earth. As the scientific community continues to analyze the data, the discovery of this tiny moon serves as a reminder of how much remains to be learned about our cosmic neighborhood. Even planets that have been studied for decades can still hold surprises. The team expects that further analysis of the telescope's imagery will continue to yield new insights into the complex nature of the outer planets.