Jupiter takes 12 years to complete its orbit about the Sun, thus it moves through the 12 zodiac constellations at the rate of one per year. You'll need to check the chart for when and where Jupiter will be visible.
Jupiter is the largest of the planets, and also very bright -- 2-1/2 times as bright as Sirius, the brightest star in the night sky. If you know when and where to look, Jupiter will be the brightest object around.
In the telescope, notice that Jupiter's disk is not round, but rather squashed and wider at the equator. This is because Jupiter is spinning so fast -- its day is only 10 hours long! On the disk itself, look for the white zones and dark belts. These bands are lined up east-west, and also the result of Jupiter's fast spin. Sometimes you can see storms, or irregularities, in the belts. If you see a pale reddish spot in the southern hemisphere, you've located the "Great Red Spot". This is a gigantic hurricane, about the size of 3 Earths. It's been observed for 300 years, so is at least that old. If you can see any detail in the bands, and are very patient, you can watch that detail move across Jupiter's disk as it rotates. It will take about 5 hours for an object to cross the disk.
The four largest moons of Jupiter are almost always visible. They'll look like tiny stars roughly lined up with Jupiter's equator. We call these the Galilean moons, because Galileo was the first to observe them. His discovery of these moons going around Jupiter helped convince people that the Earth was not really the center of the universe (although Galileo was punished for this idea). By the way, your telescope is about 2 times bigger than the one Galileo used, so you'll have a much better view than he did! The moons move quite fast, and you'll be able to see them change position during the evening. If you see fewer than 4 moons, the missing bodies are either traveling in front of, or behind, the planet. Sometimes you can see the shadow of one crossing the disk.
When all 4 moons are present, the closest to the planet is Io, bright with a slightly yellowish-orange tinge. Next comes Europa, pure white but dimmer than Io. Third is Ganymede, the brightest of all. Farthest from the planet (generally) is Callisto, the darkest.
Jupiter is a giant gas planet, made mostly of hydrogen and helium (the building blocks of the universe). Although it doesn't have any surface, the interior may be under enough pressure to have squeezed the hydrogen into a liquid, and there may be a small rocky core at the center. Most of what we see, of course, are the bright white clouds of frozen ammonia in the upper atmosphere. Places on the disk where these clouds are thin or absent shows us the lower, brownish belts of darker water and sulfur.
Sketch Jupiter and its moons. Note the date and time.
Approximate position of Jupiter in the early evening hours:
When Where to look Spring 1996 early AM only Summer 1996 east Fall 1996 west Winter 1997 not visible Spring 1997 early AM only Summer 1997 east Fall 1997 west Winter 1998 not visible Spring 1998 early AM only Summer 1998 early AM only Fall 1998 east Winter 1999 west Spring 1999 not visible Summer 1999 early AM only Fall 1999 east Winter 2000 west Spring 2000 not visible Summer 2000 early AM only Fall 2000 east
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