Moons of Uranus these five, Titania, is 1,578 km in diameter and the eighth-largest moon in the Solar System, and about one-twentieth the mass the Earth's Moon. The orbits of the regular moons are nearly coplanar with Uranus's equator, which is tilted 97.77° to its orbit. Uranus's irregular moons have elliptical and strongly inclined (mostly retrograde) orbits at large distances from the planet. William Herschel discovered the first two moons, Titania and Oberon, in 1787, and the other three ellipsoidal moons were discovered in 1851 by William Lassell (Ariel and Umbriel) and in 1948 by Gerard Kuiper (Miranda). These five have planetary mass,
Moons of Saturn came from materials in the Oort cloud, associated with comets, and not from the materials that formed Saturn in earlier times. Studies based on Enceladus's tidal-based geologic activity and the lack of evidence of extensive past resonances in Tethys, Dione, and Rhea's orbits suggest that the moons inward of Titan may be only 100 million years old. Moons of Saturn The moons of Saturn are numerous and diverse, ranging from tiny moonlets less than 1 kilometer across to the enormous Titan, which is larger than the planet Mercury. Saturn has 62 moons with confirmed orbits, 53 of which have names