When Galileo looked to the sky with his telescope in 1609 he saw the "king of the planets," Jupiter. Though it shines in the nighttime sky, it is not a star, but a distant world. Jupiter is by far the largest planet in our solar system and has many interesting features.
Jupiter is much larger than Earth -so much larger that more than 1,320 Earths could fit inside it! Jupiter is more than 317 times more massive than Earth. Jupiter was named for the "king of the gods" in mythology - Zeus in Greek mythology or Jupiter in Roman mythology was the most powerful of the gods.
If you tried to walk on Jupiter's surface you could not do so because Jupiter is a large gas giant. There is no solid surface on Jupiter. Astronomers have so far discovered that Jupiter has 63 known moons! Some astronomers estimate that the number may be closer to 400 for all of Jupiter's moons larger than 1 kilometer (0.6 miles) across. Galileo discovered four of Jupiter's largest moons when he began looking at Jupiter with his telescope about 400 years ago.
To look at Jupiter in the nighttime sky this September, you will need:
Binoculars (10x50) mounted on a tripod or a telescope in order to see Jupiter's moons
Clear night sky
Paper and pencil on a clipboard for drawing what you see
Here is what you will do:
1. Find Jupiter by looking east in the nighttime sky. It will rise around 8:45 p.m. at the beginning of September, at 7:45 p.m. by mid-September and at 6:45 p.m. by the end of September. Jupiter is very bright and does not twinkle like stars do.
2. Using a pair of good binoculars or a telescope, find Jupiter in the field of the binoculars or telescope and see if you can find four of its largest moons.
3. Draw what you see on your piece of paper.
4. Look again through the binoculars or telescope throughout the month. Does the position of Jupiter change? How does the position of the moons change? Do Jupiter's moons ever travel in front of or behind Jupiter?
Enjoy watching Jupiter throughout the month of September when it will really rule the sky. It will appear bigger and brighter than it has for 47 years on Sept. 21. Jupiter will have more detail apparent than any other object in the nighttime sky except the Earth's moon! On Sept. 21, Jupiter will be "at opposition," meaning that the Sun is opposite in the sky from where we view Jupiter from the Earth. The planet Uranus will also be at opposition and will appear close to Jupiter in the nighttime sky and will also be bigger and brighter than usual, although Jupiter will really be king of the sky for September.
Come to JupiterWatch
To see Jupiter and its moons the way Galileo did, come the JupiterWatch Event on the sidewalk outside SMART Centre Market (30 22nd St., Wheeling) beginning at 8 p.m. on Sept. 20. There will be a second JupiterWatch Event at 8 p.m. Sept. 21.
The JupiterWatch events are free and open to the public. Bring a telescope if you have one and enjoy a sight not seen for 47 years! The planet Jupiter will not be this close to the Earth again until 2022.
Build a Galileoscope
Prior to the JupiterWatch Event on Sept. 20, a parent/guardian and child team can build a Galileoscope (a telescope the same size, design and power as Galileo used) to use at the JupiterWatch Event. The parent/child will then take the Galileoscope home that they build to enjoy for years to come.
This Galileoscope Telescope Building Workshop costs $45 for the parent /child team. Only a camera tripod is needed for complete use of the Galileoscope. Participants for the Galileoscope Telescope Building Workshop must pre-register by Sept. 18.
For more information about the Galileoscope Telescope Building workshop, JupiterWatch and other upcoming events, call 304-23DINOS (304-233-4667) and visit the SMART-Center website, www.smartcenter.org