Castor as depicted in the Ark Starmap
Castor (Corel IV) is a terrestrial, desert planet that sits at the far outer edge of the Corel system's green band, in the United Empire of Earth (UEE). In 2651, Corsen Messer V ordered several companies to terraform the planet, so it could serve as an example of the capacity of Human technology. Though it was technically terraformed, the atmosphere is thin and the climate is almost intolerably cold. A handful of settlements dot Castor, primarily centered around deep ice-mining operations.