Moons of Uranus

Uranus has 27 known moons, but 5 of them(the ones covered on this page) are considered major. The image above shows Uranus at the leftmost position and six of its largest moons(from left to right: Puck, Miranda, Ariel, Umbriel, Titania, Oberon). All of these six moons are considered major moons of Uranus except Puck. A fun fact that you may or may not have noticed about Uranus's moons is that they're all named after characters from either William Shakespeare's or Alexander Pope's plays.

Properties:

Mass: 6.4 * 10¹⁹ kg

Mean Radius: 235.8 km

Semi-major Axis: 129,390 km

Orbital Period: 1.413 days

Rotational Period: 1.413 days(synchronous)

Surface Gravity: 0.079 m/(s²)

Etymology: Miranda(from The Tempest by William Shakespeare)

Miranda is the smallest and innermost major moon of Uranus. Unfortunately, not much is known about the surface of Miranda because Voyager 2 could only observe the moon's Southern hemisphere due to Uranus' sideways orbit. From what we know, however, due to the broken terrain observed on the moon, it can be inferred that the moon used to be somewhat geologically active. Interestingly, Miranda has the highest cliff in the entire Solar System. The cliff is known as Verona Rupes, with a height of 20 km.

Properties:

Mass: 1.251 * 10²¹ kg

Mean Radius: 578.9 km

Semi-major Axis: 191,020 km

Orbital Period: 2.520 days

Rotational Period: 2.520 days(synchronous)

Surface Gravity: 0.269 m/(s²)

Etymology: Ariel(sky spirit from The Tempest by William Shakespeare)

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Ariel is the moon of Uranus that orbits the second-closest(and second-smallest) out of all the major moons of Uranus. Some of the main features of Ariel would be its canyons, ridges, and craters riddled across the surface. The moon also has lots of broken terrain just like Miranda.

Properties:

Mass: 1.275 * 10²¹ kg

Mean Radius: 584.7 km

Semi-major Axis: 266,000 km

Orbital Period: 4.144 days

Rotational Period: presumably 4.144 days(presumably synchronous)

Surface Gravity: 0.2 m/(s²)

Etymology: Umbriel(from Alexander Pope)

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Umbriel is the third closest moon to Uranus. The moon is primarily composed of water-ice, with other material composing about 40% of the moon's mass. The other material is most likely mainly carbonaceous rock and organic compounds. Carbon dioxide was also observed on the surface of Umbriel in significant traces We know very little about Umbriel, just like other moons of Uranus, because we only observed it up close once when Voyager 2(launched 1977) flew by it in 1986.

Properties:

Mass: 3.400 * 10²¹ kg

Mean Radius: 788.4 km

Semi-major Axis: 435,910 km

Orbital Period: 8.71 days

Rotational Period: presumably 8.71 days(presumably synchronous)

Surface Gravity: 0.379 m/(s²)

Etymology: Titania(Queen of the fairies in A Midsummer Night's Dream by William Shakespeare)

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Titania is the largest moon of Uranus with a mean radius of 788.4 km. The surface of Titania is relatively young as evidenced by the lack of crater on the surface of Titania relative to other Uranian moons. This moon, however, has many faults and scarps(steep slopes) along with a few canyons.

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Due to traces of carbon dioxide on the surface, Titania is likely to have a CO2-rich atmosphere. Due to the relatively weak gravity on the surface of the planet, lighter gases aren't likely to exist in abundance because they wouldn't be strongly gravitationally attracted to the planet's center.

Properties:

Mass: 3.076 * 10²¹ kg

Mean Radius: 788.4 km

Semi-major Axis: 435,910 km

Orbital Period: 13.46 days

Rotational Period: presumably 13.46 days(presumably synchronous)

Surface Gravity: 0.346 m/(s²)

Etymology: Oberon(King of the fairies in A Midsummer Night's Dream by William Shakespeare)

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Oberon is the farthest major moon of Uranus. The mantle of Oberon is icy and the core is rocky, meaning there is potentially a liquid ocean layer at the core-mantle boundary. However, this is only presumed to be true because little is known about the geological history of the moon.