Uranus is the seventh planet from the Sun and the third-largest in the Solar System. It is a gas giant, composed of hydrogen, helium, and methane, and is the only planet in the Solar System that rotates on its side. URANUS is the farthest planet from the Sun that can be seen with the naked eye, and is the first planet to be discovered by telescope. It is also the second-largest planet in the Solar System after Jupiter.