Earth (also known as Sol III) is the third planet of the Sol system and was the homeworld of humanity. A class M planet it served as the capital of United Earth and then the United Federation of Planets. It had one natural satellite called Luna.
Earth had a high status in the Federation as the capital and site of the main bases of Federation agencies, such as Starfleet. It was considered by many humans to be a paradise. For these reasons it was a crucial target in any attack against the Federation and throughout history it has been attacked by various entities and states.