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Oberon (moon)

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Oberon is a very special moon orbiting the planet Uranus. It is the second-largest major moon of Uranus and the second-most massive one there. In our whole Solar System, it ranks as the tenth-largest moon.

Oberon Earth Moon Comparison
Oberon Earth Moon Comparison

This moon is quite far from its planet. It orbits Uranus at a distance of about 584,000 km. This makes it the farthest of the five major moons. One interesting thing is that Oberon is tidally locked. This means one face always points toward Uranus. Because of this, the moon's rotation matches its orbit perfectly.

Oberon symbol (fixed width)
Oberon symbol (fixed width)

What is the moon actually made of? Scientists believe Oberon is made of roughly equal parts ice and rock. It might have a rocky core at its center. This core could be about 480 km in radius. Around that core, there might be an icy mantle. A layer of liquid water could exist between the core and the mantle. This liquid layer might be up to 40 km thick.

Oberon-NASA names en
Oberon-NASA names en

It is possible that ammonia acts like antifreeze to keep the water liquid. This would happen at temperatures around 180 K. The moon likely formed from a disk of gas and dust around Uranus. This disk existed shortly after the planet itself formed.

We know a lot about Oberon thanks to a famous visitor. The spacecraft Voyager 2 flew past the moon in January 1986. This was the moon's closest approach to us. During this trip, the spacecraft took many clear images. These photos allowed scientists to map 40% of the moon's surface.

Oberon-NASA names en
Oberon-NASA names en

Before this, we had not seen the Uranian system up close. Now, we can see the different shapes on its surface. These images helped us understand its history and its many features.

William Herschel discovered Oberon on January 11, 1787. On that very same day, he also found Titania. Titania is the largest moon of Uranus. Later, in 1852, the names for the moons were suggested by Herschel's son, John. He chose names from the plays of William Shakespeare. Oberon is named after the King of the Fairies in a play called A Midsummer Night's Dream.

Oberon-NASA names en
Oberon-NASA names en

Most of the surface features also have names from Shakespeare. For example, there are large craters named Hamlet, Othello, and Macbeth. These names help us remember the moon's connection to literature.

The surface of Oberon looks very different from Earth. It is dark and has a slightly red color. This moon has more craters than any other moon of Uranus. These craters were made by impacts from asteroids and comets. The largest crater is named Hamlet and is 206 km wide.

Oberon-NASA names en
Oberon-NASA names en

You can also see deep cracks called chasmata. The most famous one is called Mommur Chasma. These canyons formed when the inside of the moon expanded. This expansion caused the icy crust to crack and split. These features tell a long story of a very old surface.

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🖼️ Images & Media (3)
File:Oberon symbol (fixed width).svg
Oberon symbol (fixed width).svg
File:Oberon Earth Moon Comparison.png
Oberon Earth Moon Comparison.png
File:Oberon-NASA names en.png
Oberon-NASA names en.png
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