Earth, also known as "Terra" in Inspector #13, is the home planet ofHumans, a few aliens, some human/alien hybrids and many animal life forms, located in the Solar System as the third planet. Earth is said to be a Level 2 planet and it appears as the common setting in many Ben 10 episodes. An odd thing about the planet is that a great deal of alien activity happens on Earth which isn't a trans-galactic level civilization. This has led to the majority of the plot lines within the Ben 10 series, as well as a major story arc within Ben 10: Alien Force.