Nine planets, including Earth, travel around the Sun. These planets, together with the Sun, form the solar system.

Click on a planet below to view its specifications.

The planets move around the Sun along oval-shaped paths called orbits. One complete path around the Sun is called a revolution. Earth takes one year, or 3651/4 days, to make one revolution around the Sun. Planets that are farther away from the Sun take longer. Some planets have one or more moons. A moon orbits a planet in much the same way that the planets orbit the Sun.

Each planet also spins (or rotates) on its axis. An axis is an imaginary line running through the center of a planet. The time it takes Earth to rotate on its axis equals one day.