Explain how Newton developed a theory to explain why the planets moved according to Kepler’s laws of planetary motion.

Well, Newton was a pretty smart cookie. He came up with his theory of universal gravitation which basically explained why the planets moved the way they did according to Kepler's laws. You see, Newton realized that there was this force called gravity that made objects attract each other. So, he figured that the same gravity that made an apple fall from a tree also kept the planets in their orbits around the sun. It's like the ultimate cosmic glue! So, Newton's theory was like the missing piece of the puzzle that explained why the planets followed Kepler's laws. Pretty nifty, huh?