JUPITER

MASS: 317.8 times Earth's
DIAMETER: 88,730 miles
ROTATION: 9 hours, 50 minutes
ORBIT AROUND SUN: 11.9 Earth years

The fifth planet, Jupiter, is the largest planet in the solar system. It is known for its Red Spot. It is caused by a mass of clouds churning counterclockwise, with winds blowing at about 250 miles per hour. The Red Spot is twice the size of Earth and has lasted more than 300 years.Jupiter's core of rock is many times more massive than Earth with pressures that are so great that hydrogen and helium gases are turned into liquid. The bulk of the planet is a deep, thick atmosphere, which consists mostly of hydrogen (86%) and helium (14%). The colorful bands of clouds that we see are actually layers of clouds.The darker clouds tend to be deeper in Jupiter's atmosphere while the lighter clouds are higher up. The atmosphere also has giant lightening storms in its upper clouds.Another one of Jupiter's unique characteristics is that it has at least 16 known moons. Amazingly the moons are different from each other: some are icy, some are rocky, some are cratered, and some are remarkably smooth. The four largest are the most popular and can be seen with a small telescope from Earth. Io, Europa, Ganymede, and Callisto, were discovered by Galileo in 1610 and are collectively called the Galilean satellites. Ganymede is the largest of the four moons. Io is the fourth largest moon. It is about the same size as Earth but it has a more volatile surface. It is the most volcanic body in the solar system. Recently, the moon Europa has been getting a lot of attention. Scientists believe there may be a liquid ocean beneath the frozen surface. If this is true then there is a chance that life may exist even on Europa's frigid terrain.Like Saturn, Jupiter has rings, although they aren't as visible as Saturn's. So far, three rings have been discovered. A flattened main ring and an inner, cloud-like ring (halo) are both composed of small dark particles. While the third ring, known as a gossamer ring because of its transparency, consists of two rings. One is embedded within the other, and both are composed of microscopic debris from two small moons, Amalthea and Thebe.