Oberon (moon)

Oberon is a large moon.

It orbits the planet Uranus. It is the farthest major moon from that planet.

The moon is made of rock and ice. It might even have a hidden ocean of water inside. This water could be deep under the ice.

Its surface is dark and red. Many big holes cover the ground. These holes were made when rocks hit the moon.

There are also giant cracks in the ice. These cracks look like long canyons. They formed a long time ago.

A spacecraft named Voyager 2 flew by in 1986. It took many pictures of the moon. This helped us learn about it.

Oberon is a large moon of Uranus. It is the second-largest major moon there. William Herschel discovered it in 1787. He named it after a king of the fairies.

The moon is made of rock and ice. It may have a rocky core. This core might be inside an icy mantle, which is a thick outer layer. A layer of liquid water might sit between them.

Oberon's surface is dark and reddish. It has many impact craters. These are large holes made by hitting rocks. The largest crater is named Hamlet. It is 206 km wide. The moon also has chasmata. These are deep canyons or cracks in the ice. They formed when the moon grew larger inside.

A spacecraft named Voyager 2 flew by in 1986. It took many pictures of the moon. These photos mapped 40% of the surface.

One side of the moon always faces Uranus. This happens because the moon is tidally locked. This means it spins at the same rate it orbits. Oberon is the tenth-largest moon in our Solar System.

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.

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.

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.

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.

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.

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.

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.

Oberon is the outermost and second-largest major moon of the planet Uranus. It is also the second-most massive of the Uranian moons. In the context of our entire Solar System, it ranks as the tenth-largest moon.

This moon is quite distant from its parent planet. It orbits Uranus at a distance of approximately 584,000 km. This makes it the farthest of the five major moons in the Uranian system. Because of its distance, its orbit lies partially outside the magnetosphere of Uranus. A magnetosphere is a magnetic bubble that surrounds a planet.

Scientists believe Oberon formed from an accretion disk. This was a disk of gas and dust that surrounded Uranus shortly after the planet formed. The moon's composition appears to be roughly equal parts water ice and rock. This density of 1.68 g/cm³ suggests it is more substantial than many moons of Saturn. It is likely differentiated into distinct layers. This means different materials have separated into layers based on their weight. The moon may have a rocky core with a radius of about 480 km. This core likely contains about 54% of the moon's total mass. Surrounding this core is an icy mantle.

There is a possibility of a liquid ocean inside the moon. This ocean might exist at the boundary between the rocky core and the icy mantle. If it exists, the ocean could be up to 40 km thick. The temperature there might be around 180 K. Scientists think substances like ammonia might act as an antifreeze to keep the water liquid. The internal structure of Oberon depends on its thermal history, which is still being studied. Some researchers believe that large moons like Uranus's may have active subterranean oceans. This would mean there is liquid water hidden deep beneath the icy surface.

Oberon's surface is dark and has a slightly red color. It is actually the reddest of the major Uranian moons. The surface is covered in many impact craters from asteroids and comets. These craters reach diameters of up to 210 km. The largest known crater is named Hamlet, and it is 206 km wide.

Because it has so many craters, scientists believe Oberon has the most ancient surface among the moons of Uranus. The surface density of craters is so high that it approaches saturation. This happens when new impacts destroy older ones at a similar rate. Many large craters, like Othello and Macbeth, have floors made of very dark material.

In addition to craters, the surface features deep canyons called chasmata. These are long, steep-sided depressions. The most prominent canyon is named Mommur Chasma. These canyons were formed by crustal extension. This means the moon's outer crust stretched and cracked. This happened because the interior of the moon expanded during its early evolution. The expansion was about 0.5% of the moon's size. This geological activity was an endogenic process, meaning it came from within the moon. These cracks helped shape the moon's appearance alongside the external impacts.

We learned much about Oberon thanks to the Voyager 2 spacecraft. It flew past the moon in January 1986. This was the closest approach to the moon. The spacecraft took many images that allowed scientists to map 40% of the surface.

Before this mission, the Uranian system had not been studied up close. Oberon is also tidally locked to Uranus. This means its rotational period matches its orbital period of about 13.5 days. Consequently, one face of the moon always points toward the planet.

William Herschel discovered Oberon on January 11, 1787. On that same day, he also discovered Titania, the largest moon of Uranus. The names for the moons were suggested later in 1852. John Herschel, William's son, suggested names from the works of William Shakespeare. Oberon is named after the King of the Fairies in the play *A Midsummer Night's Dream*. Most surface features follow this theme. For example, craters are named after characters like Romeo, Lear, and Falstaff. This connects the study of space to the history of literature.