Earth is the third planet in the solar system. Earth orbits the sun at a distance of roughly 93 million miles and is the only known planet capable of supporting life.
Earth is the largest of the terrestrial planets as well as the densest major body in the solar system. The planet possesses an iron core that produces a magnetic field that shields the surface from the effects of cosmic and solar radiation. Earth's atmosphere is able to keep its surface warm enough for liquid water without producing a runaway greenhouse effect that would result in temperatures too high to sustain life.