Earth formed circa 4.5 billion years ago, out of the cosmic dust left over from the stellar ignition of the Sun. The planet revolves around its parent star once every 365.26 days, a period known as an Earth Standard Year. Due to the tilt to Earth's axial rotation, the planet experiences four concretely defined seasons and climatic variation. Aside from being the largest terrestrial planet of Sol, it is also the system's densest. It is one of two planets in the Sol system to give rise to intelligent life.
Earth has always been at the forefront of history, maintaining its status as the epicenter of human politics. The planet houses the headquarters of the United Nations government and military.