Question

Stars appear to move from east to west because:
A) All stars from east to west
B) The earth rotates from west to east
C) The earth rotates from east to west
D) The background of the stars moves from west to east

Answer 1

Hint: Students can get a hint of the answer by recalling the instance as to when they travel in a car, the trees and the other objects on the roadside seem to be going backward as the car is travelling forward.

Complete step-by-step answer:
The motion of objects as perceived by an observer depends upon the frame of reference that the observer is present in with respect to the object. For example, a person sitting in a car sees the trees seemingly travelling backward. The truth is that the trees actually do not move but since the observer is in the car, his frame of reference with respect to the trees is moving forward along with the car.
A similar thing happens when a person on the earth observes stars in the sky. The earth rotates from west to east and hence, in this frame of reference, the stars seem to travel in the opposite direction, that is, from east to west with respect to the observer.
Therefore, stars seem to travel from east to west.

So, the correct answer is “Option B”.

Note: Students must note that the same explanation is valid as to why the sun rises in the east and sets in the west. The earth rotates from west to east and to us observers on the earth, it seems like the sun is in fact, travelling from the east (that is, rising in the east) to the west (that is setting in the west).
An interesting fact is that for a person on Venus, the sun rises in the west and sets in the east. This is because Venus rotates from east to west.