Jupiter: The Giant

Jupiter is the fifth planet from the son and was named after the the king of the Roman Gods. Jupiter is the largest object in the solar system besides the sun. It's diameter is eleven times that of the planet earth and it would take approximately 1,000 earths to fill up its enormous volume. Even the Great Red Spot of Jupiter is more than three times the diameter of the planet earth.

Here is some general information on Jupiter:

• Diameter (miles)= 88,730
• Mass (trillion trillion lbs)= 4,187
• Density (earth=1)= .24
• Gravity (earth=1)= 2.34
• Period of Rotation (hours)= 9.8
• Escape Velocity (mph)= 133,104
• Major Atmospheric Gas= Hydrogen
• Inclination of Equator (degrees)= 3.1
• Known Moons= 16
• Mean Orbital Velocity (mph)= 29,216
• Minimum Distance From Sun= 460.3 (millions of miles)
• Maximum Distance From Sun= 507.2 (millions of miles)
• Mean Distance From Sun= 483.4 (millions of miles)
• Period of Revolution (earth years)= 11.86

Here is some detailed information on Jupiter:

Surface and Atmosphere--

Layers of dense clouds prevents the surface of Jupiter from being seen from the earth. These high-level clouds consist of frozen crystals of amonia and methane. Jupiter is considered by most astronomers to be a fluid planet which means it is primarily composed of gas, but some liquid as well. However, the planet mays have a small solid core of rocky material. A series of belts and zones can be seen on Jupiter's clouds when viewed through a telescope. The belts are dark lines that circle the planet parallel to its equator. The zones are light-colored areas between the belts. Through the years, the widths and positions of the belts change. A large, oval mark known as the Great Red Spot can be seen on Jupiter's clouds. It is about 25,000 miles long, making it more than three times the diameter of the earth, and is also 20,000 miles wide. This spot slowly changes its position from year to year. It is generally believed that the spot is an intense atmospheric disturbance similar to a hurricane. It seems to consist of violently swirling masses of gas.
Jupiter's atmosphere is composed mainly of hydrogen (84 %) and about 15% helium. There are also small traces of acetylene, ammonia, ethane, mehtane, phosphine, and water vapor. Atmospheric pressure on Jupiter has never been accurately measured. The pressure is the force exerted by the weight of the gases in the planet's atmosphere. It is estimated that the pressure at the tops of the clouds are near that of earth's (14.7 lbs per sq.in.) but the pressure below is probably much greater. Most of the thick atmosphere is composed of hydrogen gas but the deep interior may consist of highly compressed liquid nitrogen. Jupiter's core seens to be made up of iron-bearing rocks. As for the planet, it is doubtful but certain microscopic organisms may be able to live in some regions of the planet's atmosphere.

Mass and Density--

No other planet in the solar system can compare to Jupiter in mass. It is about 318 times the mass of earth, however, it is of a low density. It is slightly denser than water and about a fourth as dense of the earth. The force of gravity on Jupiter, however, is much greater than the earth's. An object weighing 100 pounds on earth would weigh about 253 pounds on Jupiter.

Satellites and Ring--

Sixteen known satellites can be found orbitting the planet Jupiter. Its four largest moons are known as Galilean satellites because they were discovered by the Italian astronomer Galileo in 1610. They all have diameters greater than 1,900 miles. Two of the moons, Ganymede and Calisto, appear to be made up of equal proportions of iced rocky material. Both are covered with many craters. Europa and Io, the other two, are made of rocky material but contain little or no ice. Jupiter's other twelve satellites have diameters ranging from 9 to 106 miles. In addition to the sixteen satellites, Jupiter also has a thin ring around it. It appears to be made of fine dust particles and is much fainter than Saturn's rings. It is more than 4,000 miles wide and about 18 miles thick.

Flights to Jupiter--

It was in the early 1970's that the first flights to Jupiter began. Pioneer 10 , a U.S. space probe was the first to fly past Jupiter. It measured Jupiter's radiation belt and reported on the amount of hydrogen and helium in the planet's atmosphere. It also discovered that Jupiter has an enormous magnetic tail which is an extension of Jupiter's Magnetosphere (zone of strong magnetic forces around the planet) and is about 500 million miles long. Another unmanned U.S. space probe, Pioneer-Saturn flew by Jupiter on December 2, 1974. It took may close-up photographs of Jupiter's polar regions and reported data on its Great Red Spot, magnetic field and temperature. The U.S. Voyager 1 and Voyager 2 provided information on Jupiter's ring and also the four largest satellites. In 1989, Galileo began a six-year journeyd to Jupiter in whcih it dropped a probe to study the planet's atmosphere beneath the clouds.