Phases of the moon.

As the moon orbits the earth

We see the different phases of the moon.

This is because the moon is iluminated differently as it orbits us.

Lets start with a new moon

This is a difficult phase to see as it appears close to the sun.

as it moves we see it as a waxing cresent

after that it becomes the

first quater, when the moon makes a 90' angle between the earth and sun

on to waxing gibbous

and then the full moon - when the moon is the opposite side to the sun

then the waning gibbous

third quarter moon.

Waning cressent.

And back to a new moon

This takes a period of about 28 days.