Odin (also known as Anubis) was one of the natural satellites orbiting the UNSC colony world Hope. Its purple appearance is due to its atmospheric composition of superheated and ionized gases such as argon and helium. Odin's lethal atmosphere is strikingly similar to a closely-neighboring gas giant Epitadeus d, so it is believed that Odin must have once been a comet that had skimmed Epitadeus d's atmosphere, early in its life as a planetoid. Underneath it's deadly atmospheric veil, Odin's surface is primarily covered in plasma volcanoes. Some are so large and tall, that they breach the highest layers of the atmosphere. When plasma spews from these supermassive plasma volcanoes, it creates a rippling effect that looks like tides of water rolling on the surface of the planet's plasma-coated atmosphere.
Odin's inhospitable climate has fascinated humans for years. It is considered one of the most harsh places known to man. It has recently been dubbed Anubis after the egyptian god's association with death.