United States California Alameda, CA Irvine, CA Menlo Park, CA Santa Clara, CA Temecula, CA Illinois Abbott Park, IL Chicago, IL North Chicago, IL New York State New York, NY Pennsylvania Philadelphia, PA Texas Irving, TX Virginia Altavista, VA.
Planets orbit the Sun while moons orbit around planets. The amount of time required for a planet or moon to complete one orbit around another body is called an orbital period. On Earth, we call this orbital period a year. Our year is 365.256 days. On Mars it takes 686.98 days (Earth days, that is) to complete one orbit about the Sun--that's a long time to wait between birthdays!
Just think of a top, or record, or wheel. All these things spin around a center point which we call an axis. This type of motion is called rotation, so the amount of time it takes an object to rotate is called a rotational period. It takes the Earth 23 hours, 56 minutes to rotate on its axis. We call the rotational period of Earth a day. Mars takes just a little longer to rotate, at 24 hours, 37 minutes. The Moon is much slower than either Earth or Mars. It takes over 655 hours for the Moon to turn just once on its axis--that's more than 27 days! Second, all the planets and moons in our solar system also move around other things.