The primary reality and Earth of the DC Universe comic book canon, upon which the DC Universes Online reality and Earth is based, is known as "New Earth" following the Infinite Crisis.
While Earth is clearly visible from the Watchtower, it is far smaller than it should be from an orbital satellite. Also, the Moon and the Sun is nowhere to be seen.
Earth, like all planets, possesses a World Soul. While the Earth's soul does not make it as sentient as the planet Mogo, it is strong enough that the planet may sometimes exhibit a will of its own, which it manifests by empowering various agents to enact its will at times of need.