Third Rock from the Sun is an American sitcom that aired from 1996 until 2001 on NBC. The show is about a group of extraterrestrials on an expedition of what they consider to be the least important planet, Earth (the 3rd Rock from the Sun), while posing as a human family of four, to observe human beings.The premise of the show revolves around an extraterrestrial research expedition attempting to live as a normal human family in the fictional city of Rutherford, Ohio, where they live in a loft apartment. Humor was principally derived from the aliens' attempts to study human society and, because of their living as humans themselves while on Earth, to understand the human condition. In later episodes, they became more accustomed to Earth and often seemed to be more interested in their human lives than in their mission.