Jupiter, the fifth planet out from the Sun, is the largest planet in our solar system (11 times larger than Earth).
Naturally, Jupiter has not one, not two, but four planet-size moons. The Old Farmer’s Almanac for Kids shares with us the awesome names of each moon!
Giant Jupiter and its Many Moons
Io (Eye-oh) – The Pizza Moon
Think of a giant pizza, with melted cheese, tomato sauce, and ripe olives. That’s what Io, the most volcanically active body in the solar system, looks like. “Toppings” on the surface are actually sulfur in different colorful forms. Jupiter’s strong gravity causes 300-foot-high “tides” in Io’s solid surface. (The difference between the lowest and highest ocean tides on Earth is “only” about 60 feet!)
Europa - The Ocean Moon
Think of Earth’s South Pole, a frozen mass with an ocean underneath. That’s Europa. Under an icy crust, Europa may have oceans as deep as 30 miles or more. Altogether, Europa is believed to have twice as much water as Earth.
Ganymede – The Rocky Moon
Think of a huge, magnetic rock. With a diameter of 3,280 miles, Ganymede has mountains, valleys, craters, and lava flows covered with rock and ice, plus its own magnetic field. Ganymede is Jupiter’s largest moon and the largest in our solar system. If it orbited the Sun instead of Jupiter, it would be a planet.
Callisto – The Oldest Moon
Think of a dimpled golf ball. That’s Callisto. About 4 billion years old, Callisto has the oldest landscape in the solar system, the most craters, and no volcanic activity.
Learn more fun facts about the universe in The 2015 Old Farmer's Almanac, now available!