NASA’s James Webb Space Telescope has revealed a previously unknown moon orbiting Uranus, bringing the planet’s total to 29. The discovery, announced by a team led by the Southwest Research Institute (SwRI), adds a small but important piece to the picture of Uranus’ dynamic system.

NASA said a tiny moon has been found by the Webb Space Telescope orbiting the planet Uranus. The moon is only six miles wide and was found by Webb’s near-infrared camera, The Associated Press reported. That’s about the length of a 10K. Scientists believe that it was missed for so long because it is tiny and is faint, the AP reported.