how do you tell the diference betwen a moon and a planet

Question: how do you tell the diference betwen a moon and a planet
- Keywords:
  difference,
  moon,
  planet
Asked by glopy889 to Rob on 14 Mar 2011 in Categories: Space.
- Robert Simpson answered on 14 Mar 2011:
  
  A moon is something that orbits a planet. There are moons in our solar system that are as big as some planets (Jupiter has four very large Moons that are similar to Mercury in size) but because they orbit a planet they are called moons.

Question: how do you tell the diference betwen a moon and a planet