Earth was the home-planet of the human race, and was located in the Solar System. The planet was destroyed by a planetary nuclear warhead during Solar War IV. Only a handful of humans escaped the planet's destruction, and they have since dispersed among the universe.
Pre-Solar War IV
The terrain of Earth prior to its destruction was perhaps the most diverse terrain on any known planet. It's surface was covered with water with lush forests, great mountain ranges, and arid deserts sprawling on the dry land. Most of the planet was colonized by humanity at the time of its destruction.
Post Solar War IV
Earth underwent massive destructive changes during the war. Most of the oceans dried up, and the once great mountain ranges were mined down to mere hills in order to supply materials for war-machines or for ammunition when people began to run out of bullets. The forests on the planet were burnt down and deserts now occupy the locations of once sprawling plains. The planet's surface is now covered with toxic levels of radioactive waste.