Planetary Motion

Introduction to Astronomy
Observation Projects

| Setting Sun | Moon Phases | Astrophotography | Ursa Major | Measuring Earth | Star Count | Meteor Shower | Planet Motion | Moon's Orbit | Star Atlas | Sun Diameter | Variable Star | Sun Spots | Artificial Satellites | Rainy Day Projects | Design Your Own |

IX. Observing the Motion of the Planets.

(This is a longer term project requiring a few minutes a week for about 2 months.)

  1. With care you can chart the motion of the planets through the heavens. If you are lucky, your planet will start or end a retrograde loop during your observation and you will have personal experience with the funny motions in the sky that so mesmerized our ancestors for thousands of years! You will need a detailed star chart which you can get from your instructor. You will have the best luck with the closest planets (Venus and Mars) which are close to both the Earth and Sun, although Jupiter and Saturn will work as well. (To do Jupiter and Saturn you will need to be very accurate with your measurements!) If you have a camera on which you can hold the shutter open for long periods of time, then you can also do this project astrophotographically.  See your instructor before you attempt this method. 
  2. Plot the position of the planet(s) on your star chart at least once a week. Be sure to date each recorded position.
  3. In what general direction (East or West) does the planet move relative to the stars? Is the motion constant in speed? If not, why not? If you where able to plot two planets, which one moved faster and why?


Copyright 2005, Department of Physics, Weber State University, Ogden UT 84408-2508

Revision: 8/23/2003 JES, 1/18/2005 ATJ