Satellite's low point (4)
I believe the answer is:
moon
This clue is a double definition.
'satellite's' is the first definition.
(moon is a kind of satellite)
'low point' is the second definition.
(I've seen this before)
(Other definitions for moon that I've seen before include "Reveal rear" , "Phoebe" , "High light" , "Earthly satellite" , "Satellite of six Down" .)