Ariel (moon)

Ariel is one of the major moons of Uranus, discovered in October 1851 by William Lassell. It is the fourth largest moon of Uranus and is named after a character from Shakespeare's play "The Tempest". Ariel orbits Uranus at a close distance, making it one of the planet's five major moons, alongside Miranda, Umbriel, Titania, and Oberon.

Discovery and Naming

Ariel was discovered on October 24, 1851, by William Lassell, a British astronomer who also discovered several other moons of Uranus. The moon was named after a spirit in Shakespeare's play "The Tempest", following the tradition of naming Uranian moons after characters from the works of Shakespeare and Alexander Pope. The name "Ariel" was suggested by John Herschel, son of William Herschel who discovered Uranus.

Orbit and Rotation

Ariel orbits Uranus at a distance of about 190,000 kilometers (118,000 miles), making it the closest of the planet's five major moons. It completes an orbit around Uranus in about 2.5 Earth days. Ariel's orbit lies inside Uranus's magnetosphere, which means it is directly exposed to the planet's magnetic environment. This exposure is thought to have a significant impact on Ariel's surface.

Ariel is tidally locked with Uranus, meaning that the same side of the moon always faces the planet. This is a common characteristic of many moons in the Solar System.

Physical Characteristics

Ariel is an icy moon with a diameter of about 1,158 kilometers (720 miles), making it the fourth largest moon of Uranus. Its surface is composed of a mixture of water ice and rock, with a high reflectivity indicating a relatively young and geologically active surface compared to other Uranian moons.

The surface of Ariel is marked by numerous craters, canyons, and ridges. The most prominent features include vast canyon systems that can reach up to 10 kilometers (6 miles) in depth, indicating significant tectonic activity in the past. Ariel's surface also shows signs of cryovolcanism, where water and other volatiles are expelled from the interior, suggesting an internal heat source.

Exploration

Ariel has been studied primarily through observations made by the Voyager 2 spacecraft during its flyby of Uranus in January 1986. Voyager 2's images and data provided invaluable insights into Ariel's geology, surface composition, and physical properties. However, due to the limited close-up observations, many aspects of Ariel's geology and composition remain poorly understood.

Future missions to Uranus and its moons are proposed to further explore Ariel and its sibling moons. These missions aim to study the moons' geology, internal structures, and potential for hosting subsurface oceans, which could have implications for understanding the habitability of icy moons in the outer Solar System.

See Also

• Moons of Uranus
• Exploration of Uranus
• List of natural satellites