Earth

The third planet from a star named the Sun. Features six continents, four oceans, and many countries. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen. Earth has a single large Moon that is about 1/4 of its diameter and, from the planet's surface, is seen to have almost exactly the same angular size as the Sun.

With its abundance of liquid water, Earth supports a large variety of life forms, including potentially intelligent species such as dolphins and humans.