Below is a diagram of the earth-moon system. You
can drag the moon in its orbit around the earth. The moon and earth are
illuminated by the sun shining from the lit side of the moon.
Each time you press "NEW SUN ANGLE" the sun is
given a new random direction (different time of year) and the moon
phase in lower right is given a new random phase (different time of the
month).
Your job is to orient the moon in its orbit around
the earth so that an observer on the earth will see the moon phase of
the lower left.
Press "TEST YOUR POSITION" to see if you get the
phase correct. The phase according to your moon's position will be
displayed in lower right.
Repeat the “NEW SUN ANGLE” until
you consistently get the correct answer.
Animator
Physlet developed by Wolfgang Christian and Mario Belloni of Davidson
College.
Script
written by Donald Collins of Warren Wilson College. Funded in
part by the Appalachian College Associan, Teaching and
Technology: Stage II, Andrew W. Mellon Foundation.