Project Goal: To observe the changing yearly positions of the planets in the sky.
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
In the upper left hand corner of the movie screen you will see the date and time (7 A.M. Eastern Standar Time) for each movie frame starting in March of the year 2001 and ending in March of the year 2025. The time step between each frame is one year.
Extending the Earth's orbital plane (the ecliptic plane) out to the celestial sphere produces an intersection which is a circle known as the Ecliptic. The ecliptic is the yearly path of the Sun. It is the white curve in each frame of the movie.
For a discussion of the motions of celestial objects see Voyage 1.
Step through each frame of the movie and observe the Changing Yearly Positions of the Planets.
Print or copy the Project Results Form on which to record you answers and hand it in to your instructor.
Results Form
Name____________________ Student Number__________ Class ______________
Date ____________________
Based on your observations:
1. Which planets change their yearly positions most slowly?
2. Which planets appear to always be closest to the ecliptic?
3. Which planet is farthest from the ecliptic?
4. Why don't planets move exactly along the ecliptic as does the Sun?
5. Describe how the yearly speed at which planet positions change relates to increasing distance from the Sun.
6. How does the change in position relate to a planet's sidereal period of revolution around the Sun?
6. What causes the change in positions?