Why does the Moon change shape?
● The Moon itself doesn’t change shape, it just appears to do so. It’s how much of
we can see that changes.
● The Moon is made mainly of rock and doesn’t produce any light itself. We only
see the Moon when the Sun is shining on it.
● The portion of the Moon that we see depends on its position relative to the Earth
and the Sun.
● The Moon orbits the Earth every 29.5 days. This is also the same amount of time
it takes the Moon to rotate once on its axis meaning that the same side of
the Moon always ends up facing us down on Earth.
● When the Moon is between the Earth and the Sun, the side facing us is
Predominantly dark and we can only see a small portion of it. As the Moon
continues its orbit and eventually reaches the opposite side of the Earth to where
the Sun is, the entire side of the Moon facing us becomes lit by the Sun and we
can now see a full Moon.