Earth takes approximately 24 hours to complete one full rotation on its axis relative to the Sun, which defines the length of a solar day
. More precisely, this period is about 23 hours, 56 minutes, and 4 seconds when measured relative to distant stars, known as a sidereal day, which is slightly shorter than the solar day because of Earth's orbit around the Sun
. The 24-hour rotation period causes the cycle of day and night. Earth's axis is tilted about 23.5 degrees relative to its orbit, which, combined with the rotation, results in seasonal changes
. The rotation speed varies with latitude, being fastest at the equator at about 1670 kilometers per hour and slowing to nearly zero at the poles
. In summary:
- Solar day (relative to the Sun): ~24 hours
- Sidereal day (relative to distant stars): ~23 hours 56 minutes 4 seconds
This difference arises because Earth moves along its orbit while rotating, requiring slightly more than one full rotation for the Sun to return to the same position in the sky
