The term "Novan" is used to describe describe the group of Human colonists who settled the planet Terra Nova, and their descendants. The term is applied to these colonists in much the same way the term Martians is applied to those living on Mars.
In late 2078, the Novans were forced to live underground after the atmosphere of their planet was poisoned from an asteroid impact.
In 2151, the Earth starship Enterprise visited Terra Nova to discover the whereabouts of the apparently missing colony. The Enterprise crew discovered the Novans, who did not believe that they were related to the Terrans, and who they blamed for the poisoned air. Captain Jonathan Archer was able to convince them that they were in fact Humans and helped transplant them to a poison-free region of the planet. (ENT: "Terra Nova")