Earth

Earth (aka Terra) is the only planet in the real universe known to support life.

Earth is a small planet orbiting an average yellow-dwarf star (sometimes called Sol) near the outer rim of a barred spiral galaxy called the Milky Way. Earth is its name in the commonly-used language, English. It has a single, very large natural satellite referred to as "the Moon" or Luna.

Earth figures prominently as the homeworld of the human species in a great number of science-fiction stories, shows, movies, and books. The characteristics of Earth are commonly used in versus debates when the characteristics of an inhabited planet are needed for some kind of calculation.

Key Measurments

• Radius = 6,371 km
• Depth of crust = 40 km
• Depth of mantle = 2700 km
• Mass = 5.974E24 kg
• Core density = 9.5E3 kg/m³
• Crust density = 2.8E3 kg/m³
• Mass of ocean water ~ 1.4E21 kg
• Orbital radius around Sol = 149.6 million km (1 AU)

Earth in Star Trek

In Star Trek, Earth is the capital of the United Federation of Planets and the center of most of the Federation's research and manufacturing facilities, especially those related to Starfleet.