The real facts about Jupiter

Jupiter is the fifth planet from the Sun and by distant the largest. Jupiter is above twice as huge as all the additional planets combined. Jupiter is about 90% hydrogen and 10% helium (by numbers of atoms, 75/25% by mass) with traces of methane, water, ammonia and "rock". This is very near to the composition of the primordial Solar Nebula from which the full solar system was formed. Saturn has a related composition, but Uranus and Neptune have much fewer hydrogen and helium.

Jupiter is the fourth shinning object in the sky (after the Sun, the Moon and Venus). It has been recognized since prehistoric times as a bright "wandering star". However in 1610 when Galileo first pointed a telescope at the sky he revealed Jupiter’s four large moons Io, Europa, Ganymede and Callisto (currently known as the Galilean moons) and recorded their motions back and forth just about Jupiter. This was the first finding of a center of motion not it seems that centered on the Earth. It was a most important point in favor of Copernicus's heliocentric theory of the motions of the planets (along with other new facts from his telescope: the phases of Venus and the mountains on the Moon). Galileo's outspoken support of the Copernican theory got him in mess with the Inquisition. Today anyone can replicate Galileo's observations (without fear of retribution :-) using binoculars or a cheap telescope.

Jupiter and the added gas planets have high velocity winds which are confined in broad bands of latitude. The winds blow in reverse directions in adjacent bands. Slight chemical and temperature differences between these bands are in charge for the colored bands that govern the planet's appearance. The brightness colored bands are called zones; the dark ones belts. The bands have been identified for some time on Jupiter, but the complex vortices in the boundary regions between the bands were first seen by Voyager. The data from the Galileo probe specify that the winds are even faster than expected (more than 400 mph) and make bigger down into as far as the probe was able to view; they may extend down thousands of kilometers into the center. Jupiter's atmosphere was also found to be pretty turbulent. This indicates that Jupiter's winds are determined in large part by its internal heat fairly than from solar input as on Earth.