Review: Moon phases

What causes moon phases?

The moon phases are caused by the moon's position relative to Earth and the sun.

New Moon

The new moon is when the moon is between Earth and the sun. The moon is not visible.

Full Moon

A full moon occurs when the Earth is between the sun and the moon. The entire moon is lit.

Difference between waxing and waning

Waxing means the moon is getting larger; waning means it is getting smaller.

Crescent Moon

A crescent moon is a small sliver of light visible. It's seen before and after a new moon.

Gibbous Moon

A gibbous moon is more than half lit but not full. It is after the first quarter.

True or false: The moon phases take 28 days.

True, because one complete cycle of moon phases takes about 29.5 days.

Fill in the blank: A _______ moon is fully illuminated.

full

Quarter Moon

A quarter moon appears as half of the moon is lit. It can be first or last quarter.

What phase comes after a waxing gibbous?

The next phase is a full moon.

How many main phases are there?

There are eight main phases of the moon: new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, last quarter, and waning crescent.