Moon

A moon is a round rocky object that orbits a planet.  Earth has one moon that takes 29 days to orbit.  It also takes 29 days for the moon to rotate once.  This means that we only see the one side of it at any time.  The only way we can see the moon is when the sun shines on it.  There are 8 phases of the moon.  A phase describes the changing shape of the moon that we see.  It starts with a new moon where we cannot see any part of the moon lit up.  It is between the sun and Earth.  As more of the moon can be seen it is called waxing, then as less of the moon can be seen, it is known as waning.  When the moon is more than half-lit is called a gibbous moon.  When the moon is less than half lit is called a crescent moon.  The full moon is when the Earth is between the sun and moon.  The tides are the rise and fall of the ocean.  They are made from the gravitational pull of the moon and sun on the Earth.  A lunar eclipse is caused when the moon passes through the shadow of the Earth.  It can last up to half an hour.