Orcus

Orcus is a large trans-Neptunian object (TNO) located in the Kuiper Belt. It's about half the size of Pluto and was discovered in 2004.  

Here are some key facts about Orcus:

• Size: It's about 910 kilometers in diameter, making it one of the largest TNOs.

• Orbit: Orcus is a plutino, meaning it's in a 2:3 orbital resonance with Neptune. This means it orbits the Sun twice for every three orbits of Neptune.  

• Moon: Orcus has one known moon named Vanth.  

• Surface: The surface of Orcus is relatively bright and rich in water ice.  

Orcus is a fascinating object that provides valuable insights into the formation and evolution of our solar system.