Answer:
Retrograde Motion
- Perspective effect caused when Earth passes a slower moving outer planet that makes the planet appear to be moving backwards relative to the background stars
Geocentric
- Earth-centered model of the universe
Heliocentric
- Sun-centered model of the universe
Eclipse
- When one celestial body passes into the shadow of another celestial body
Foci
- Two points on the interior of an ellipse that are used to define its shape
Gravity
- Force of attraction between two objects
Inertia
- Tendency of an object to resist changes in its motion
Step-by-step explanation:
self-explanatory, I hope this helps