How can we predict how the moon will change appearance from day to day?

1. When you see the moon, think of the whereabouts of the sun

2. The moon rises in the east and sets in the west, each and every day

3. The moon takes about a month (one month) to orbit the Earth

4. The moon's orbital motion is toward the east

The slice of sunlight continues to decrease until the moon is a waning crescent and then a new Moon. The whole cycle (from new Moon to new Moon) takes about 29.5 days. If you have a hard time remembering which way the moon phases go, just think: "white on right, getting bright!"