Moon
The moon is a large natural satellite that revolves around the earth. It has a diameter of about 2,160 miles (3,475 km). The moon travels around the earth in an egg-shaped orbit. When it is nearest to the earth it is 221,463 miles (356,334 km) away. From new moon to new moon, it takes the moon 29 days, 12 hours, and 44 minutes to circle around the earth. It takes the moon this same amount of time to spin around once on its own axis. For this reason the same half of the moon always faces the earth.