Assertion: mercury's motion | /r/HasProperty | apparent change
Facets:
value: within a system
type: LOCATION
value: in movement of a planet
type: OTHER
value: in a direction
type: OTHER
Source sentences:
text: Retrograde motion is an APPARENT change in the movement of the planet through the sky.
text: Retrograde motion is the apparent change in movement of a planet in a direction opposite to other planets within a system.