East-West Motion

Explain the apparent east-west motion of the night sky

Imagine you are facing south. Now think of a ball moving from left to right (east to west). This is the direction the Sun appears to move in the sky.

We know the Earth goes around the Sun and not the other way around.

Let us imagine the ball hangs in the air. How would you have to move your head to ‘see’ the ball moving from east to west? You would have to move from west to east.

If you hovered above the Earth, above the North Pole, you would see the Earth move counter clockwise.


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Courtney Seligman, Professor of Astronomy The Motion of the Sky at Different Latitudes


Explain why the sky appears to move from east to west when we know the Earth rotates.