How long for moon to orbit earth?

Earth and the Moon orbit about their barycentre (common center of mass), which lies about 4,600 km (2,900 mi) from Earth's center (about 3 / 4 of the radius of Earth). On average, the distance to the Moon is about 385,000 km (239,000 mi) from Earth's center, which corresponds to about 60 Earth radii. read more

If you draw the elliptical orbit of the moon, and you measure the time it takes to go around the ellipse as it slides through space, you get the siderial orbital period. That is 27.3 days. But that "sliding through space" is actually following Earth's orbit, which itself curves around the Sun. read more

Earth Views from the Space Station's High Definition Earth-Viewing System NASA 139 watching Live now Science - Universe - Phases of Moon - English - Duration: 8:49. read more