NASA, ESA, CSA, Matthew Tiscareno (SETI Institute), Matthew Hedman (University of Idaho), Maryame El Moutamid (Cornell University), Mark Showalter (SETI Institute), Leigh Fletcher (University of Leicester), Heidi Hammel (AURA)

On Tuesday, March 11, 2025, the International Astronomical Union confirmed the discovery of 128 new moons around Saturn, bringing the total number to a whopping 247 moons! Jupiter has the second most moons, at 95, about a third of Saturn’s moons. These moons were found by a team of astronomers from Taiwan, Canada, the US, and France using the aptly named Canada France Hawaii Telescope (CFHT) located on Mauna Kea in Hawaii in 2023, and they were confirmed this month.

What makes a moon a moon?
NASA defines moons as natural satellites, which means they are not human-made, and they travel around a planet, or an asteroid in some cases.The first moon discovered was, of course, the Moon, Earth’s one and only. In the early 1600s, Galileo discovered the first moons around another planet, the Galilean moons of Jupiter. From then on we started finding many more! Moons come in all shapes and sizes, from round and 3,275 mi across like the largest moon Ganymede, to potato shaped and 7 miles across like Dactyl, the moon of the asteroid, 243 Ida.

About these new moons!
The newly found moons of Saturn are mostly small and irregularly shaped. Several observations over the last two decades have hinted at the existence of these moons, but astronomers had not been able to confirm their orbits (paths around the planets) to prove they are satellites and meet the requirements of NASA’s moon definition. In 2019-2023 astronomer Edward Ashton at the Academia Sinica Institute of Astronomy and a team of other incredible astronomers received time on the CFHT and were able to get enough observations of these moons to map their paths around Saturn. This was aided by the position of Saturn in our sky at the time, since it happened to be in front of Aquarius, a constellation with faint stars making it easier to see the small moons. As astronomers learn more about these moons, they are also investigating why Saturn has so many moons compared to the other planets. But for now, Saturn maintains its record of the most moons in our solar system!