Jupiter and Saturn’s Moon Counts Reach New Highs

The solar system’s two gas giants, Jupiter and Saturn, have added to their already impressive collection of moons. Recent discoveries announced by the Minor Planet Center (MPC) bring Jupiter’s total to 101 and Saturn’s to a staggering 285 [1]. This brings the total number of known moons orbiting planets and dwarf planets in the solar system to 442.

New Discoveries Announced

On March 16, 2026, the MPC revealed the addition of four moons to Jupiter’s orbit and eleven to Saturn’s [2]. These newly discovered satellites are relatively small, averaging around 1.9 miles (3 kilometers) in diameter [3]. Their faintness and distant orbits made them challenging to detect, requiring observations from powerful ground-based telescopes.

Who Made the Discoveries?

The four new moons of Jupiter were discovered by astronomers Scott Sheppard of the Carnegie Institution for Science and David Tholen of the University of Hawaii, utilizing the 6.5-meter Magellan–Baade telescope at Las Campanas Observatory in Chile and the 8-meter Subaru telescope atop Mauna Kea in Hawaii [3]. The eleven new moons orbiting Saturn were found by a team led by Edward Ashton at the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan, using the 3.5-meter Canada–France–Hawaii Telescope on Mauna Kea. Ashton previously led a team that discovered 128 new moons of Saturn in 2025 [3].

The Ongoing Search for Moons

Both Sheppard and Ashton are prolific discoverers of moons in the solar system, each having over 200 discoveries to their names, many of which are co-discoveries [3]. As telescope technology and observational methods continue to improve, astronomers anticipate discovering even more moons around Jupiter, Saturn, and other celestial bodies.

Current Moon Counts in the Solar System

Here’s a summary of the current moon counts for planets and dwarf planets in our solar system:

• Earth: 1
• Mars: 2
• Jupiter: 101
• Saturn: 285
• Uranus: 28
• Neptune: 16
• Venus: 0
• Mercury: 0
• Pluto: 5
• Eris: 1
• Makemake: 1
• Haumea: 2
• Ceres: 0

Future Missions May Reveal More

While Saturn currently holds the lead in the moon count, upcoming missions to Jupiter, such as the Europa Clipper and the Jupiter Icy Moons Explorer (JUICE), could potentially uncover additional satellites when they arrive in the Jovian system in the early 2030s [2].

Where to Discover More Information

The discoveries were formally announced in Minor Planet Electronic Circulars: MPEC 2026-F09, F10, F11 and F12 for Jupiter, and MPEC 2026-F14 for Saturn [3]. The Minor Planet Center serves as the central clearinghouse for astronomical discoveries, including asteroids, comets, centaurs, and moons [4].