1. Natural Satellites
   1. A small or secondary planet which revolves around a larger one.
   2. There are 171 moons, or natural satellites that orbit the planets in our solar system.
2. Artificial Satellites
   1. A man-made object placed in orbit around an astronomical body.
   2. Types
      1. Geostationary Satellite/ Communication Satellite
         1. an earth-orbiting satellite, take 24 hours to orbit the Earth
         2. used to provide visible and infrared images of Earth's surface and atmosphere for weather observation, oceanography, and atmospheric tracking.
      2. Polar Satellite
         1. polar orbits, takes approximately 90 minutes to complete one orbit
         2. used for monitoring the weather, military applications (spying) and taking images of Earth's surface