How many moons does Saturn have?

Updated October 19, 2026 · 5 min read

Saturn has 274 confirmed moons, the largest tally of any planet, following the announcement of 128 new moons in March 2025. Only about two dozen of them are large or well studied; the vast majority are small irregular satellites a few kilometers across, found with deep telescope surveys. The number has climbed from one moon in 1655 to 274 today, and it is likely to grow again.

The March 2025 announcement

In March 2025 the International Astronomical Union's Minor Planet Center recognized 128 new moons of Saturn, discovered by a team led by Edward Ashton (Academia Sinica, Taiwan) using the Canada-France-Hawaii Telescope on Mauna Kea. The team had already found 62 new Saturnian moons announced in 2023; the new batch came from tracking further faint candidates over several years until their orbits around Saturn were secure.

The technique is called shift-and-stack. Astronomers take a series of images of the region around Saturn, then shift each frame at the rate a moon at a given distance would move across the sky, and add them together. A moon too faint to appear in any single frame builds up into a visible dot, while background stars smear out. Repeated over many plausible motion rates, the method reveals objects only a few kilometers wide at a distance of 1.4 billion km.

Nearly all of the 128 are irregular moons: distant, inclined and mostly retrograde (orbiting opposite to Saturn's rotation). Most belong to the Norse group, and their numbers and clustering suggest they are fragments of a few larger captured bodies that were shattered in collisions, some of them possibly quite recently on solar-system timescales.

How the count grew: a timeline

The early discoveries are covered in famous astronomers of Saturn; individual moons are listed in the list of Saturn's moons.

The classical era: nine moons in 250 years

For more than two centuries, finding a moon of Saturn required the best telescope of its day. Titan was visible in Huygens' modest refractor because it is huge. Cassini's four moons, including Iapetus and Rhea, came with the long telescopes of the Paris Observatory. Herschel's 40-foot reflector revealed Mimas and Enceladus, which hug the bright planet. Phoebe in 1899 was the first moon of any planet discovered by photography rather than by eye.

Ring-plane crossings and spacecraft

Small inner moons are drowned in the glare of the rings, except when Earth passes through the ring plane and the rings nearly vanish (see why the rings disappear). Crossings in 1966 and 1980 yielded Janus, Epimetheus and several co-orbital moons. The Voyager flybys of 1980 and 1981 then imaged shepherd moons such as Prometheus and Pandora at close range. Cassini, in orbit from 2004 to 2017, added small moons inside and near the rings, such as Methone, Pallene, Polydeuces, Daphnis, Anthe and Aegaeon.

The irregular-moon boom

Since 2000, the count has been driven almost entirely by ground-based surveys of the space far from Saturn, where irregular moons orbit as far as about 25 million km from the planet. Large digital cameras on 4- to 8-meter telescopes (CFHT, Subaru, and others) made it possible to detect bodies of a few kilometers. In 2019 a team led by Scott Sheppard announced 20 new moons, giving Saturn 82 and briefly the lead over Jupiter; the 2023 and 2025 announcements put Saturn far ahead.

Why the number keeps changing

There is no official minimum size for a moon, so the count is really a measure of how faint our telescopes can see. Three rules of thumb explain the moving total:

• Confirmation takes years. A faint dot near Saturn could be an asteroid passing in the background. It only counts once it has been followed long enough, usually over more than one year, to prove it orbits Saturn.
• Ring particles are not counted. Saturn's rings contain countless bodies from dust to house-sized boulders, plus moonlets that leave "propeller" disturbances in the rings. None of these is on the moon list.
• Small moons vastly outnumber big ones. For irregular moons, the number of objects rises steeply as size drops. Researchers expect many more Saturnian moons smaller than the current limit of a few kilometers, waiting for bigger telescopes.

Saturn's lead over Jupiter probably reflects its history rather than luck: its irregular population appears to include several families of fragments produced by collisions, some possibly recent on solar-system timescales, and each such breakup multiplies the number of small moons.

Sources

• NASA Science: Saturn's moons
• IAU Minor Planet Center
• JPL Solar System Dynamics: planetary satellite discovery circumstances
• Sheppard, S. S., et al., 20 new Saturnian moons announced by the Carnegie Institution for Science, October 2019