The minus sign indicates a relative motion toward the Earth.

But in fact they are in relative motion with respect to one another.

A perfect match of relative motion was rare, even now.

Built around an understanding of objects in relative motion, it is still used today.

His decision would be based on relative motion, not acute perception.

Maybe the relative motions won't mean anything at all.

To perform the operation, relative motion is required between the tool and the work.

However first accurate data is needed of the target's position and relative motion.

The relative motion is the same as if one were orbiting.

This is equivalent to the relative motion of the target ship.