Does absolute motion only exist in outer space?

No, absolute motion is not limited to outer space. Absolute motion refers to the motion of an object relative to a fixed reference point or frame of reference. It does not depend on the location or environment in which the motion occurs. Therefore, absolute motion can exist anywhere, including on Earth, in the atmosphere, or in any other physical space.

In practice, however, it can be difficult to determine absolute motion since any measurement or observation of motion is always made relative to some frame of reference. However, in theoretical discussions and certain physical contexts, the concept of absolute motion is used to describe motion without relying on a particular reference frame.