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Home Page of Peggy E. Schweiger


1. DETERMINE THE MOON'S SIDEREAL MONTH AND ITS SYNODIC MONTH: Observing the phases of the moon-observe the moon every few days as it progresses from new moon to full moon and then one more time near the time of the next new moon. Collect the following data: a) find the position of the moon with respect to nearby stars. Plot this position on a start chart, b) estimate the angle between the sun and the moon by estimating the angle between the moon and the sunset point and adding 15 degrees for each hour since sun set, and c) make a drawing of the moon corresponding to each of your observation dates, accurately drawing its appearance.

2. DIURNAL MOTION OF THE SUN: At intervals during the day, mark the point on cardboard where the shadow of the sun falls from a gnomon. Begin observations before noon and make at least one observation per hour, with observations every fifteen minutes when the sun is near its maximum altitude. Find the altitude of the sun at each observation time. Estimate the direcion of true north on your paper. Measure the azimuth of the sun at each observation. Calculate the maximum altitude of the sun and at what time this occured.

3. DIAMETER OF THE SUN: Use a reflected image of the sun to produce an image of the sun. Knowing the geometry of your setup and the distance to the sun, you can calculate its diameter.

4. APPARENT MOTION OF THE SUN; Determine the motion of the sun with respect to a bright star in the east and one in the west. Take observations over several weeks at the same time to calculate the rate of change in altitude. Also, observe the sunset point and record its rate of change.

5. THE ROTATION PERIOD OF THE EARTH: Use reference stars to the east and to the west of Polaris. Determine their position angle with respect to Polaris. Make the following measurements: a) altitude of each star, b) the angle between Polaris and each star, and c) the position angle of the star with respect to Polaris. Take measurements over a night. Use data to calculate the rate at which the earth rotates.

6. THE MOTION OF THE PLANETS: Observe the planets' motion over several weeks. Plot their positions on star charts to deduce their rate of motion across the sky and determine whether or not they are in retrograde.