Project 12

Project Goal: To observe the moons of Jupiter.

What you Need for This Project

To do this project you will have to be able to view the movie clip included with this project.  All Macs come with a version of QuickTime and computers running Windows have a movie viewer called Media Player.  The movie clip should play using either type of computer or player.

If your computer does not have QuickTime movie viewer installed you can download the Macintosh or Windows version from the internet by clicking on QuickTime.  Also, an installable version of QuickTime is included on the StarryNight CD program disk.

Start the movie and watch as the inner planets as they orbit the Sun.  Drag the horizontal scroll box to the left to rewind to the first frame of the movie.  Clicking once to the right of the scroll box will advance to the next time frame.  Alternately, if you are using a QuickTime viewer, you can click the right arrow at the end of the scroll bar.  Each click advances one time frame forward.  The left arrow allows you to step backward in time.  

What You Need to Know for This Project

For a discussion of Galileo's observations of Jupiter's moons see Voyage 9.   You might also want to review material in Voyage 1.

Click on Evening January 07, 1610 to see the sky as Galileo saw it when for the first time he pointed his small telescope at Jupiter.  Step through each frame of the movie Galileo's Observations of Jupiter's Moons and observe the moons day by day as he observed them over a number of evening begining on January 07, 1610.  Almost every evening one or more of Jupiter's moons pass between the Earth and Jupiter.  These events are called transits.   Sometimes one can see the shadow of the moons cast on the upper cloud cover of the planet.  Click on A Transit of the Moons to view such an event.

The ring systems of Jupiter, Saturn, Uranus, and Neptune are made up of thousands and thousands of small objects circling the planets like tiny moons.  To view the most extensive ring system click

Based on your observations:

1. Do you think the Moon may have hindered Galileo's observations of Jupiter?  Why or why not?

2. Using each frame of the movie make a sketch of the positions of Jupiters moons,starting on the evening of January 07, 1610.

3. Compare each of your sketches with Galileo's on the same dates.  Try to explain any differences between what your observations and those of Galileo.

4. Describe what you saw as you watched the transits of Jupiter's moons.

4. Using the Jupiter's Moons Today movie sketch and identify the moons and their changing positions.

5. About how long does it take Io to revolve once around Jupiter?   _________________

6. The moons of Jupiter obey Kepler's laws of planetary motion Voyage 1..  Based on your observations list the moons in order of increasing distance from Jupiter.

7. Make a sketch of Saturn and its ring system.