Moon

1. The natural satellite of Earth, visible by reflection of sunlight and having a slightly elliptical orbit, approximately 356,000 kilometers (221,600 miles) distant at perigee and 406,997 kilometers (252,950 miles) at apogee. Its mean diameter is 3,475 kilometers (2,160 miles), its mass approximately one eightieth that of Earth, and its average period of revolution around Earth 29 days 12 hours 44 minutes calculated with respect to the sun. American men have landed on the moon.
2. A natural satellite revolving around a planet. Saturn has 62 moons with confirmed orbits, 53 of which have names, and only 13 of which have diameters larger than 50 kilometers.