Golden Age

Humanity Once was a very prosperous race, having colonized their entire solar system. Not much is known about this golden age, such as when it aproximately began, or when it ended. How it ended is also enigmatic, but it is known that some force began to attack humanity, and drove it back to planet Earth. A strange moon like thing known as the Traveler defended what was left of the human race, and through some means sacrificed itself to save humanity. The survivors of the conflict banded together and built a city underneath where the traveler hung over the earth. Humanity had been saved, but its golden age was over. Aproximately seven hundred years from the present day, enough time has passed since the travelers final stand that many details about the golden age and how it ended, such as what attacked us and exactly how the traveler saved us have been forgotten.