Jupiter
...d to slightly brown. Rarely the spot fades completely. The edge of the spot moves at 225 mph. The spot stays in the same place under the equator though it does move from east to west. In order the four largest moons are Io, Europa, Ganymede, and Calisto. These four moons are known as Galilean Satellites because they were discovered by the Italian astronomer Galileo in 1610. The United States has sent 6 probes to Jupiter. Pioneer 10 was launched in 1972. The probe reveled severe effects of Jupiter’s radiation. This probe also reported the amount of hydrogen and helium on the planet’s atmosphere. Pioneer-Saturn arrived within 27,000 miles of Jupiter’s atmosphere in 1974. This probe provided data on the “ Red Spot” and the polar regions of Jupiter. Voyager 1 And Voyager 2 flew past Jupiter in 1979. These probes carried better equipment than the Pioneers did. Astronomers used the photographs taken by the Voyagers to make the first detailed maps of the Galilean Satellites. The Voyagers also discovered sulfur volcanoes on Io, lightning on Jupiter’s clouds, and mapped flow patterns of clouds. Ulysses was launched in 1990. The European Agency built the probe mainly to study the sun’s polar regions. Scientists used Jupiter’s tremendous gravitational force to put Ulysses in an orbit that would take it over to the sun's polar regions. Scientists used Jupiter’s tremendous gravitational force to put Ulysses in an orbit that would take it over to the sun’s polar regions. As Ulysses passed it gathered data indicating that the sun’s solar wind has a much greater effect than earlier measurements had suggested. Galileo began it’s journey in 1989. In July 1995 the craft released an atmospheric probe. In December 1995 the probe plunged into Jupiter’s atmosphere. One of the most important missions Galileo had was to measure the amount of water in the atmosphere. Also in December 1995 Galileo went into orbit around Jupiter. It monitored Jupiter’s atmosphere and observed the planet’s major satellites. Galileo was designed to orbit for two years and completed it’s mission on December 1997. Next it carried out an extended mission that ended December 1999. Galileo then continued it’s observations under an extended mission known as the Galileo Millennium Edition. As for life on Jupiter it doesn't sound so good. It contains high gravity, high pressure, strong winds ...