GeneralAnswersv1

Why does the Moon have phases?

Our viewing angle changes how much of its sunlit half we see.

Output

A repeating sequence from new Moon through full Moon and back

Input

The Moon orbiting Earth while the Sun lights half of it

Input

The Moon orbiting Earth while the Sun lights half of it

A repeating sequence from new Moon through full Moon and back

Relationship

As the Moon moves around Earth, the visible fraction of its illuminated hemisphere changes.

science.nasa.gov: Why does the Moon have phases?science.nasa.govUS-PUBLIC-DOMAIN