Why is there a 4-minute difference between the solar day and the sidereal day?
A) because the Earth's rotation is variable, due to the pull of the Moon
B) because the stars slowly change their orientations in the Galaxy
C) because the Earth is going around the Sun in the course of a year
D) because the Earth's axis is tilted by about 23 degrees
E) no one knows the reason; we just have to accept the difference as an unsolved mystery

Question

Quizplus · Accepted Answer

The 4-minute difference between a solar day and a sidereal day is due to the Earth's orbit around the Sun. As the Earth rotates on its axis, it also moves a small distance along its orbit. This means that it has to rotate a little more than one complete turn for the Sun to return to the same position in the sky, resulting in a solar day that is about 4 minutes longer than a sidereal day, which is measured by the Earth's rotation relative to the stars.

Why Is There a 4-Minute Difference Between the Solar Day