 According to radiometric dating and other sources of evidence , Earth formed about 4 @.@ 54 billion years ago . Earth gravitationally interacts with other objects in space , especially the Sun and the Moon . During one orbit around the Sun , Earth rotates about its own axis 366 @.@ 26 times , creating 365 @.@ 26 solar days or one sidereal year . Earth 's axis of rotation is tilted 23 @.@ 4 ° away from the perpendicular of its orbital plane , producing seasonal variations on the planet 's surface within a period of one tropical year ( 365 @.@ 24 solar days ) . The Moon , Earth 's only permanent natural satellite , by its gravitational relationship with Earth , causes ocean tides , stabilizes the orientation of Earth 's rotational axis , and gradually slows Earth 's rotational rate . 
