Question

What concept is essential to understand how the earth-moon-sun system works?

A. Gravity
B. The number of moons around each planet
C. Planetary motion
D. Elliptical orbit

Answer 1

C) Planetary motion
It describes or defines the movement of planets in the solar system

Answer 2

C. Planetary motion

Step-by-step explanation:

planetary motion is the concept that is required to understand how moon sun system works so basically if you want to understand it clearly you have to learn Kepler's laws of planetary motion.