Rohan Acharya

Grade: 10

School: Bagmati Boarding Secondary School

City: Sukedhara, Kathmandu

Topic: Oberon

---

Beyond two gas giant planets there exists an unknown world full of mysteries orbiting the third gas giant (Uranus), Oberon. It is the second-largest moon being discovered by William Herschel on 11 January 1787. Its heavily cratered surface and the high mountains that arise about six kilometers off its surface make it more mysterious and interesting. Voyager 2 being the only flying-probe to take few images of its surface makes us more curious and invent new ideas to learn about it.

This partly seen world was named by Herschel’s son John after the characters from Shakespeare’s A Midsummer Night’s Dream take roughly about 13.5 days to complete a single revolution of Uranus. Being close to Uranus makes Oberon tidally locked. As Oberon is too far from the Sun, its temperatures can go as low as -203 degrees Celsius.

From the heavily cratered surface of the Oberon, it's clear that it had a violent origin. Oberon is thought to have the most cratered surface among all Uranian satellites. It was formed in the accretion disk that was left from Uranus’ formation which coalesced for thousands of years. Like Uranus’s other moon, Oberon is also believed to be composed of equal amounts of ice and solid rock. It might have an icy mantle and inner rocky core.

In the images provided by Voyager 2, canyons called chasmata and craters were also noticed. As the northern hemisphere was shrouded in darkness when the spacecraft took pictures, less than 50% of the surface had been mapped. Oberon might also have a liquid ocean at the core-mantle boundary. If the liquid ocean is discovered, there would be high expectations for organic molecules. Exploring this unknown cold world might lead to some groundbreaking and exciting discoveries which would help us to explore the vast universe.