Jupiter is a gas giant that is the fifth planet from the Sun. It is the largest planet in our solar system and is primarily composed of hydrogen and helium gas. It has an extremely strong magnetic field and is best known for its colorful bands of clouds and the Great Red Spot, a massive storm that has been raging for at least 400 years. Jupiter has at least 79 known moons, four of which are large and easily visible with a small telescope.