Step outside after the sun sets and you will be greeted by a pair of remarkable celestial bookends. To the west, high in the sky is a brilliant shining object. Venus, the Roman Goddess of Love and Beauty, is certainly living up to her name on these delicious summer evenings. Now turn east and cast your eyes to the other bright object. This is Jupiter. If you look close by you will see a reddish colored star. This is Antares which is the brightest star in the constellation Scorpio.
Jupiter was named for the Roman God of Everything. He is Numero Uno, the Big Cheese. Over 90% of the entire mass of the solar system, excluding the sun, is in this leviathan. Yet Jupiter could float in water; it is made entirely of gas. With a composition nearly the same as that of the sun mostly helium and hydrogenit’s considered a failed star. Its nuclear furnace just didn’t have enough mass to get totally fired up but it still emits more energy than it receives.
Unlike the white reflective clouds of Venus, Jupiter’s clouds are a symphony of colors. Astronomers have been observing prominent features for years. They’ve seen colored bands on Jupiter’s surface. These are clouds of ammonia and sulfur moving at different velocities. Jupiter’s foremost feature is the Great Red Spot. This planetary pimple was first observed over 300 years ago and is thought to be a gigantic atmospheric disturbance twice the size of the earth.
Galileo first discovered the largest moons of Jupiter in 1633. Those observations and others he made and wrote about lent credence to the theory that the Sun was the center of the known universe not the Earth. This was antithetical to the teaching of the church and Galileo was censured and confined to house arrest for the rest of his life for his beliefs.
With a good pair of binoculars and a steady hand you can often see four Galilean moons. The motion of the innermost moon, Io, is so rapid that you can detect its movement in a single night. At last count there were 63 Jovian moons, some of them only a couple of miles across.
By the way the Catholic Church finally got around to apologizing to Galileo in 1992.
This is Michael Ellis with a Perspective.