The moon does not count as a planet. It is a natural satellite that orbits Earth. According to the International Astronomical Union (IAU), a planet must meet three criteria:

* It must orbit the Sun.

* It must have enough mass to be round.

* It must have cleared the neighborhood around its orbit.

The moon meets only the first criterion. It orbits the Sun along with Earth, but it is too small to be round and has not cleared the neighborhood around its orbit. There are many other objects in the solar system that orbit the Sun, such as asteroids and comets, but they are not considered planets either because they do not meet all of the IAU criteria.