Question

1. which term describes a moon that orbits a planet in a backward motion?

dwarf planet
barycenter
satellite
retrograde

Explanation:

A retrograde motion refers to an object moving in the opposite direction to the general motion of most objects in its system. In the context of a moon orbiting a planet, retrograde means it orbits in a backward - motion compared to the typical orbital direction. A dwarf planet is a celestial body in orbit around the Sun. A barycenter is the center of mass of two or more bodies that are orbiting each other. A satellite is a general term for an object that orbits a larger body, but it doesn't specifically denote backward - motion.

Answer:

D. retrograde