Saturn & Jupiter Moons: New Discoveries & What is the Minor Planet Centre?

Astronomers have confirmed the discovery of 15 new moons orbiting Jupiter and Saturn, bringing the total number of known moons in our solar system to 442, according to announcements made this month by the Minor Planet Center (MPC).

The MPC, operating at the Smithsonian Astrophysical Observatory under the International Astronomical Union, is the official body responsible for collecting and verifying observations of minor planets, comets, and the moons of the outer planets. The newly identified moons consist of four orbiting Jupiter and eleven orbiting Saturn. These discoveries were made by separate teams: the Jovian moons were found by Scott Sheppard and David Tholen, while the Saturnian moons were identified by a team led by Edward Ashton in Taiwan.

The newly discovered satellites are small, approximately 3 kilometers (1.9 miles) in diameter, and faint, with magnitudes ranging from +25 to +27. This makes them difficult to detect, requiring repeated observations with large ground-based telescopes like the Magellan-Baade telescope in Chile and the Subaru telescope in Hawaii.

With these additions, Saturn now boasts 285 confirmed moons, significantly surpassing Jupiter’s total of 101. The discoveries were announced in circulars released by the MPC, specifically MPEC 2026-F14 for Saturn and MPEC 2026-F09 through F12 for Jupiter.

The MPC plays a critical role in tracking near-Earth objects (NEOs) that could potentially pose a threat to Earth, working in conjunction with NASA’s Planetary Defense Coordination Office. It maintains a database to predict the trajectories of these objects and alerts the scientific community to new discoveries or celestial events through electronic circulars, facilitating coordinated observation efforts worldwide.

As telescopes and observational techniques continue to improve, astronomers anticipate discovering even more moons around Jupiter and Saturn, further expanding our understanding of the outer solar system. The sheer number of moons orbiting Saturn, spanning a distance equivalent to five times the diameter of Earth, highlights the vastness and complexity of these planetary systems.