Editor's note: This article was updated March 25 at 11:40 a.m. ET to account for the recent discovery of new moons around Saturn and Jupiter. The total number of planetary moons and small-body satellites has been updated multiple times since this article was first published.
If you look up on a clear night, the brightest and largest object in the sky will probably be the moon. And unless you have a decent telescope, it is the only natural satellite you can see with your own eyes. As a result, most people have a warped perception of what a moon is and how common these natural satellites really are.
