If shifted up or down, only a slight change in star motion rate would occur (this appears to be the way the jet plume is actually directed) but so would horizon motion, so it would have to measured as absolute screen position.
(only a slight change in star motion rate; would occur; ) (this; appears; ) (it; to measured; as absolute screen position) (this; to be; the way the jet plume is actually directed) (the jet plume; is actually directed; )
only a slight change in star motion rate this it this the jet plume
would occur appears to measured to be is actually directed
as absolute screen position
the way the jet plume is actually directed