Not only that, the black globe would block out the microwave backgroundRichardP said:Yes, but as it gets close it will blank out the stars and anything else behind the globe. Eventually a significant portion of the sky as viewed by the target ship goes completely black, automated sensors will spot that.
radiation, so any microwave sensor would easily spot it as a moving "hole"
in the background radiation - it would stand out like a moving black spot
on a white sheet of paper.