Question

A student notices that the moon is full one evening. Which sequence of moon phases will the student observe over the next eight days?

Answer 1

The moon's phases directly depend on the positioning of the moon toward the Earth, as well as its position toward the sun. The moon is always half lighted, though we can not see that, and we can only observe from the Earth part of the lighted half of the moon, depending on how the moon and our planet are positioned toward one another. The only time that we actually see the whole half of the moon that is lighted is when we see full moon, which from our perspective seems like all of the moon is lighted.

After we see a full moon phase, in the next eight days we can observe the waning gibbous moon phase, and the last quarter phase. The waning gibbous moon phase is when the lighted part is decreasing from our perspective, while the last quarter is when we see half bright and half dark moon, with the left side being the bright one.