Phases of the Moon Lab In this exercise, you will investigate the cause of the phases of the Moon. The figure below shows an orbital diagram of the Earth-Moon system as viewed from above the Earth's north pole. Light from the Sun is coming from the left. Note that the drawing is not to scale. Section I Shade in the part of the Moon that is in shadow and the part that is unobservable from Earth in each of the eight numbered positions. The first has been completed as an example. (Use dark shading for the shadow, light cross- hatch for the unobservable side.)

Section II Record the phase and appearance of the Moon in Table 1 for each of the eight positions in the diagram. (Again, the first has been done as an example.) Position 1 Position 2 Position 3 Position 4

waxing crescent 45°

Position 5 Position 6 Position 7 Position 8

Last updated: Wed Jan 19 11:11:35 EST 2000 http://helios.astro.lsa.umich.edu/Course/Labs/moon_phases/moon_phases.html

Conclusion Questions: 1. Describe how the shape of the moon changes during one orbit.

2. An eclipse can occur when the Sun, Earth, and Moon line up (a lunar eclipse is when the Moon passes into the Earth's shadow, a solar eclipse is when the Moon's shadow falls on the Earth). At what phase can a lunar eclipse occur? At what phase can a solar eclipse occur?

3. Simulate each of these types of eclipses with your model Moon. Which type was easier to make? Based on this, which type do you think would be the most common to see?