Jupiter (a.k.a. "Jove") was the King of the Roman Gods and the patron of the Roman state. To the ancient Greeks, he was known as Zeus, ruler of the Greek Gods and Mount Olympus.

This is the symbol for Jupiter:


Jupiter is the fifth planet from the Sun and by far the largest of all nine planets. Jupiter is more than twice as massive as all the other planets combined - It's 318 times bigger than the Earth!

Jupiter does not have a solid surface due to its gaseous composition. The swirls and bands we see when looking at Jupiter are the tops of clouds high in its atmosphere.


Jupiter has high speed winds that whip by at more than 400 mph! These winds are trapped in the planet's wide bands of latitude. Each band has a slightly different chemical make-up and temperature from the others. This gives it a color which is different from surrounding bands. The light colored bands are called "zones." The dark colored bands are called "belts."


The vivid colors seen in Jupiter's clouds are probably the result of subtle chemical reactions in Jupiter's atmosphere. The clouds are a different color, depending on its altitude. Blue clouds are lowest, followed by brown and white clouds. Red clouds are the highest. Sometimes we see the lower cloud layers through holes in the upper cloud layers.


Jupiter's most outstanding and interesting feature is called "The Great Red Spot." The Great Red Spot is an oval about 12,000 km by 25,000 km - big enough to hold two Earths! Jupiter also has other smaller similar spots. The Great Red Spot is a high-pressure region whose cloud tops are much higher and colder than the surrounding areas.


Jupiter has faint rings like Saturn's, but much smaller.  Unlike Saturn's, Jupiter's rings are dark. They're probably composed of very small grains of rocky material.



Look for Jupiter! When it is in the nighttime sky, Jupiter is often the brightest "star" in the sky (it is second only to Venus, which is seldom visible in a dark sky). The four large Galilean moons are easily visible with a pair of binoculars. You can even see a few of Jupiter's bands and the Great Red Spot with a small astronomical telescope!