Earth, also known as Terra or Sol III, is a planet in the Solar System in which most of the activity outlined on Infinite Histories takes place. It is the third planet from the sun and the only known location in the Solar System with life on its surface.
Earth is highly varied geographically and ecologically. It has polar ice caps and a warm tropical equator. As Earth is tilted on its axis by around 23 degrees, it experiences seasons of hot and cold in the regions between the equator and the poles.