If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet?
A)The planet is actually two bodies, one moving toward us, the other away from us.
B)The planet is rotating.
C)The planet is in the process of formation.
D)The planet is in the process of falling apart.

Question

Quizplus · Accepted Answer

If one edge of the planet is redshifted and the opposite edge is blueshifted, it suggests that one side is moving away from us and the other is moving towards us. This could be explained by the planet rotating, with one side moving towards us as it rotates towards us and the other side moving away from us as it rotates away from us.

If We Observe One Edge of a Planet to Be