Earth's moon shines brightly in our sky, but it is not the only satellite in our solar system. Experts estimate there are as many as 170 to 180 moons orbiting the eight planets of our section of the galaxy. A moon is defined as a satellite that orbits a planet. Moons are named after Roman and Greek gods and demigods — with colors and mystifying landscapes that match their fanciful namesakes. Here's our look at some of the beautiful, bold and essentially unexplained moons of our solar system. Pictured here is a false color image from NASA of Saturn's moon, Rhea.