A student went outside every night for eight nights to look at the Moon. The pictures below show how the Moon looked each night.

Question

Images courtesy of NASA
What caused the changes in the appearance of the Moon that the student observed?
A.
the revolution of the Moon around the Earth
B.
the revolution of the Earth around the Sun
C.
the rotation of the Moon on its axis
D.
the rotation of the Earth on its axis

Answer 1

The changes in the appearance of the Moon that the student observed are caused by:

A. the revolution of the Moon around the Earth

As the Moon orbits the Earth, the angle at which sunlight hits the Moon changes, leading to different phases of the Moon (new moon, crescent, first quarter, gibbous, full moon, and back). This is what the student observed over the eight nights.