Thus the latter may be interposed between the end of the shadow--the only part of the shadow really visible--and the eye; but the end of the shadow _cannot_ be interposed between the satellite and the eye.

If a satellite _on the disc_ were eclipsed by another satellite, the black spot thus formed would be in another place from the black spot on the planet's body.

I mention all this because, simple as the question may seem, I have known careful observers to make mistakes on this subject.

A shadow is seen crossing the disc and overtaking, apparently, a satellite in transit.

It seems therefore, on a first view, that the shadow will hide the satellite, and observers have even said that they have _seen_ this happen.