Lunar Phases

For this exercise, you will need a bright lamp to represent the Sun (or if it's sunny, go outside and use the real Sun!), and a small ball (or a piece of fruit - cantaloupe works especially well!) to represent the Moon. Standing with your back to the source of light, hold the ball up at arms length.

(a) If the `Sun' is behind you, what time of day is it?

(b) You are looking up at the ball/Moon--what phase is it?

(c) Move the ball/Moon to the left, in the direction that it orbits the Earth. Can you see the shadow increase?

(d) Continue moving the ball/Moon in its orbit--when does it become (i) new; (ii) first quarter; (iii) third quarter; (iv) full? (See Figure 1.14 in the textbook for a diagram if necessary.)