If an observer on Earth sees the Moon to be at first quarter, then at the same time, an observer on the Moon would observe Earth to be at what phase?
A)first quarter
B)third quarter
C)full
D)Earth does not appear to go through phases when observed from the Moon.

Question

Quizplus · Accepted Answer

When the Moon is at its first quarter phase as seen from Earth, an observer on the Moon would see the Earth at its third quarter phase. This is because the phases of the Earth as seen from the Moon are opposite to the phases of the Moon as seen from Earth. When one is in its first quarter, the other appears to be in its third quarter due to the relative positions of the Earth, Moon, and Sun.

If an Observer on Earth Sees the Moon to Be