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!
How long does it take for Neptune to rotate on its axis? The planet Neptune takes about 16 hours, 6 minutes, 36 seconds for  one complete rotation, as evidenced by its visible outer  atmosphere. This is a day on Neptune.   â¦  That's about 2/3rds of an earth day. Note that the period of  rotation is measured by watching Neptune's magnetic field.