After 22 years of Uranus having 28 confirmed moons, the gas giant was recently confirmed by researchers at the Southwest Research Institute (SwRI) to have a 29th moon after careful analysis of data obtained from NASA’s James Webb Space Telescope (JWST). The team estimates the newly discovered moon has an approximate diameter of 6 miles (10 kilometers). Until now, the smallest moons have been estimated to be approximately 11 miles (18 kilometers) in diameter, which are Cupid, Mab, and Trinculo.
“As part of JWST’s guest observer program, we found a previously unknown satellite of the ice giant, which has been provisionally designated S/2025 U 1,” said Dr. Maryame El Moutamid, who is a lead scientist in SwRI’s Solar System Science and Exploration Division in Boulder, Colorado. “This object, by far the smallest object discovered to date, was detected in a series of 10 long exposures obtained by the Near-Infrared Camera.”
S/2025 U 1 orbits approximately 35,000 miles (56,250 kilometers) from the center of Uranus, making it one of the closest objects orbiting the gas giant. For context, Uranus’ largest moons, Miranda, Ariel, Umbriel, Titania, and Oberon, have orbits of 80,690 miles (129,858 kilometers), 118,638 miles (190,930 kilometers), 165,273 miles (265,982 kilometers), 271,093 miles (436,282 kilometers), and 362,538 miles (583,449 kilometers), respectively.
JWST near-infrared composite image of Uranus and its moons. (Credit: NASA, ESA, CSA, STScI, M. El Moutamid (SwRI), M. Hedman (University of Idaho))
JWST has been primarily used to study objects outside the solar system like exoplanet atmospheres, galaxies, and stars. But this isn’t the first time it has been used to observe objects within the solar system, as it has used its powerful near-infrared instruments to observe Jupiter, Saturn, and Neptune, enabling scientists to gain significant knowledge about these intriguing worlds and what they can teach us about exoplanets and potentially finding life beyond Earth.
How many more undiscovered moons orbiting Uranus will scientists discover in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Wikipedia, EurekAlert!