Earth[]
The largest of Sol's four terrestrial planets, Earth is the third closest planet to Sol, the sun of the system. It is the densest and fifth-largest planet of the eight in the Sol System.
Home to millions of species, notably humans, Earth is the most fitting discovered planet for life. As the human's home planet, Earth has become subject to an absolutely massive amount of growth. Just over two-hundred years ago, Earth rested at seven billion in population. Even after the Federation invented space travel, the population continued rising to sixteen billion - the highest of any Federation planet.
71% of the Earth's surface is covered in saltwater. During the terraforming of other Federation planets, such as Brisch and Strelitzia, planetary engineers attempted to copy the Earth's unique hydrosphere. Earth's magnetic poles, tilted to the side about 23.4°, are coated in solid ice sheets and glaciers.
Just over 31% of Earth's mass is iron, commonly used to construct buildings and battlecruisers. Another 30% consists of oxygen, the second most necessary building block of life after hydrogen.
Earth's moon, Luna, is home to much of the Federation's Fleet bases. Tereshkova Base, a Fleet training facility, and the several Luna Bases, defense stations, help defend Earth from the meteors launched by the Arachnids.