Amaterasu is a human colony, home to Ashley Williams' mother and sisters. It lies about a dozen light-years from the Czarnobóg Fleet Depot and is one of the smaller Alliance colonies. In 2181, Ashley took a week of extraordinary leave to return home to take care of her youngest sister, Sarah.

Amaterasu is a terminus on the Illium-Amaterasu shipping lane. In 2185, as security advisories are being issued against travel to human colonies, none are issued for Amaterasu, possibly due to its proximity to an Alliance base.