Jupiter is the largest planet in the solar system. It measures 88,846 miles across. It is so massive the earth could fit itself into this giant swirling mass of low density atmospheric gaseous clouds 1,000 times. It is so large in fact it has four large moons encircling it, and many smaller only recently discovered. There may be more. At last count there were 49 in all. Admittedly, some of these may only be smaller stars, therefore expect the unexpected where Jupiter is concerned and this applies to astronomy in general. . Its facts keep changing as astronomers and space probes get better - and closer- at detection. Although large, it is lightweight in that it has little, if any solid surface as earth does.
In the past several years there have been six unmanned space probes encircling Jupiter learning its secrets. The first of these were the Pioneer 1972 that managed to get within 81,000 miles of its surface. What waslearned? Jupiter was more magnetic than at once thought and astronomers were likewise warned of the rough treatment space craft could expect when entering jupiter's fierce zones. Also, this interplanatary experiment measured the hydrogen and helium content of the planet's atmosphere.
Since, with each succeeding voyage, space craft have edged closer to. Pictures were taken when the Pioneer-Saturn got within 43,000 miles in December 1974. The next crafts, the Voyagers 1 and 2, furnished astronomers with even more information. The pictures taken allowed maps to be constructed which showed probabilities of how Jupiter looked and interacted within its space. In 1990 The Europeans space probe, Ulysses helped astronomers learn even more.
Their task was to study the sun's polar regions. Jupiter, with its magnetization and forces of gravity managed to help spin Ulysses into its gravitational field where its mission was to learn some sun facts and also, as a sideline, to report on the solar wind of Jupiter. In 1989 Galileo made its trip into space where it stayed for many years and probed and snooped until it was forced to crash into Jupiter's atmospherical space.
Before it began its extended orbit, it took measurements of water, clouds and chemicals and gave scientist much welcomed information. Running out of gas it was put out to pasture and was directed away from Europa. Since water had been found, or was thought to have been found on this moon, the astronomical fear was that if the space probe - the spy from earth - crashed on its own into this moon it would render useless whatever life giving sources that possibly were there. A noble concern to say the least, especially since the probe was of foreign substance.
Jupiter itself has a "swirling mass of gas" that is reminiscent of a hurricane. It in itself is massive as it goes around and around. (Much has since been learned of this by the various scientific maneuvers in the last twenty years. The angrier the force, the redder the bands that swirls around.) The band at its widest is triple the size of the earth and is either brownish red to brown. Its intensity varies but it never completely fades away. Scientist say possibly sulfur and phosphorus cause this color. (A giant liver spot maybe or a shingle? Who knows for sure? ) In brightness it is only second to Venus. It is the fifth planet from the sun. This is five times farther than the earth is from the sun.
Galileo discovered the four moons and they are named Io, Ganymede, Europa, and Callisto. All are named after Greek or Roman Goddesses, or wives of Jupiter. (Ganymede was a beautiful young boy and grew into an enticing man.)These four are called the Galilean satellites. They are passive little lunar lights shining in the night sky and are in themselves reason for much awe and wonder. They each have their own peculiarities: Ganymede, a mythological cupbearer to the gods, is the only moon to have magnetized fields.
Europa possibly has an ocean underneath her glaciated crust. The legend goes that Zeus, the head god on mount Olympus, was so charmed by this beautiful young girl he disguised himself as a white bull and enticed her to get on his back and when she did he flew away to Mount Olympia leaving her family and her sisters grieving. Frozen lakes and ocean may still yet be discovered beneath Callisto and Ganymede.
Callisto is pockmarked by many craters on her frozen exterior. Io, in her Greek legend life was also loved by the fickle Zeus. To hide her from Hera, his wife, he changed this concubine into a heifer. Callisto is also the wife of Zeus and is the mother of Arcus, their son. Arcus, in astronomy is the Little Bear. Better still, he had Arcadia named after him. This honor because he taught them agriculture and taught them how to spin wool.
Jupiter in Greek is Zeus and the moons are named after his paramours. So what if I throw in a little French here? By the time the naming gets done for Jupiter's moons, who knows for sure how many more will be found. we may find Marie Antoinette among them. Well, maybe not. Jupiter is nothing but a big ball of gas mixed with some liquid and has no solid surfaces. Or a least none have been discovered. Its makeup seems to be on multicolored clouds; the color depending on the color at the most predominant color at the time of viewing.
Jupiter is fast. It revolves faster around the sun than the earth revolves around the sun; to our 24 hours to make it around the sun, it speeds on around in 9 hours and 56 minutes. But how do we know how fast it is? Where do all these statistics come from? They come from radio signals that can be picked up by earth's astronomy equipped radios. What more can we say about this giant planet other than it is a circling mass that completes one cycle every tweve years, or therabouts.
http://solarsystem.nan.gov/planets Zimmerman, J.E., Dictionary of Classical Mythology, New York, 1964, Bantam Books