How many days does the moon take to complete 1 revolution around the earth?

Answer 1

The Moon takes one circle around the Earth in a little less than 27 days and 8 hours. But since the Moon is circling the Earth while the Earth is circling the Sun, the time it takes the Moon to go from full moon to the next full moon (a lunar month, so to speak) is about 29 1/2 days (29 days, 12 hours and 44 minutes). An interesting note: The ancient Mayan's were keen observers of the night sky. At the ruins of the Mayan city of Palenque, archeologists discovered that over 1200 years ago the Mayan astronomers had calculated the length of a lunar month to an accuracy of within 25 seconds of its actual value!

Answer 2

Relative to the background stars and ignoring the earth position relative to our sun, the moon takes 27 days 7 hours and 43 minutes to orbit the earth - the sidereal orbit.

During this time, the earth has progressed around the sun a little, on its orbit around the sun. For the moon to get back to exactly the right phase, it takes a little longer, 29 days, 12 hours and 44 minutes in total from full moon to the next full moon. This is known as the synodic period. The moon will have made just over one orbit relative to the background stars, and will have moved round slightly to be in front of some different stars to those at the previous full moon.

Answer 3

It takes 27.322 days to go around the Earth once. Source: http://www.windows.ucar.edu/tour/link=/the_universe/uts/moon1.html&nl=8l

Answer 4

28 days