As of 2026-10-12, Io tops the list with 2,530,000,000 km3.
- #1 Io — 2,530,000,000 km3
innermost of the 4 Galilean moons of Jupiter
Io is the innermost and second smallest of the four Galilean moons of Jupiter. Slightly larger than Earth's Moon, Io is the fourth-largest natural satellite in the Solar System, has the highest density and strongest surface gravity of any natural satellite, and the lowest amount of water by atomic ratio of any known astronomical object in the Solar System. Read more on Wikipedia.
Wikidata - #2 Titania — 2,065,000,000 km3
largest moon of Uranus
Titania is the largest moon of Uranus and the eighth-largest moon in the Solar System, with a diameter of 1,577 km. Discovered by William Herschel in 1787, it is named after the queen of the fairies in Shakespeare's A Midsummer Night's Dream. Its orbit lies inside Uranus's magnetosphere. Read more on Wikipedia.
Wikidata - #3 Enceladus — 67,113,076 km3
natural satellite orbiting Saturn
Enceladus is the sixth-largest moon of Saturn and the 18th largest in the Solar System. It is about 500 kilometres in diameter, about a tenth of that of Saturn's largest moon, Titan. It is covered by clean, freshly deposited snow hundreds of meters thick, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon reaches only −198 °C, far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide variety of... Read more on Wikipedia.
Wikidata - #4 Proteus — 34,000,000 km3
moon of Neptune
Proteus, also known as Neptune VIII, is the second-largest moon of Neptune and the planet's largest inner satellite. Discovered by Voyager 2 in 1989, it is named after Proteus, the shape-shifting sea god in Greek mythology. Proteus is about 400 km (250 mi) in diameter and orbits Neptune in a nearly equatorial orbit at a distance of about 4.75 Neptune radii from the planet's center. Read more on Wikipedia.
Wikidata - #5 Mimas — 32,600,000 km3
moon of Saturn
Mimas is the seventh-largest natural satellite of Saturn. With a mean diameter of 396.4 kilometres or 246.3 miles, Mimas is the smallest astronomical body known to be roughly rounded in shape due to its own gravity. Mimas's low density, 1.15 g/cm3, indicates that it is composed mostly of water ice with only a small amount of rock, and study of Mimas's motion suggests that it may have a liquid ocean beneath its surface ice. The surface of Mimas is heavily cratered and shows little sign of... Read more on Wikipedia.
Wikidata - #6 Amalthea — 2,430,000 km3
moon of Jupiter
Amalthea is a moon of Jupiter. It has the third-closest orbit around Jupiter among known moons and was the fifth moon of Jupiter to be discovered, so it is also known as Jupiter V. It is also the fifth-largest moon of Jupiter, after the four Galilean moons. Edward Emerson Barnard discovered the moon on 9 September 1892 and named it after Amalthea of Greek mythology. It was the last natural satellite to be discovered by direct visual observation; all later moons were discovered by photographic... Read more on Wikipedia.
Wikidata - #7 Puck — 2,225,000 km3
moon of Uranus
Puck is the sixth-largest moon of Uranus, and its largest inner moon. It was discovered in December 1985 by the Voyager 2 spacecraft. Following the convention of naming Uranus's moons after characters from Shakespeare's literary works, its name was taken from A Midsummer Night's Dream. Read more on Wikipedia.
Wikidata - #8 Portia — 1,300,000 km3
moon of Uranus
Portia is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 1. The moon is named after Portia, the heroine of William Shakespeare's play The Merchant of Venice. It is also designated Uranus XII. Read more on Wikipedia.
Wikidata - #9 Epimetheus — 843,000 km3
moon of Saturn
Epimetheus is an inner satellite of Saturn. It is named after the titan Epimetheus, the brother of Prometheus and son of Iapetus. Read more on Wikipedia.
Wikidata - #10 Juliet — 632,000 km3
moon of Uranus
Juliet is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 2. It is named after the heroine of William Shakespeare's play Romeo and Juliet. It is also designated Uranus XI. Read more on Wikipedia.
Wikidata