Final answer:
Johannes Kepler is known for discovering the elliptical orbit in which the planets move.
Step-by-step explanation:
The person known for discovering the elliptical orbit in which the planets move is Johannes Kepler. He was a German astronomer and mathematician who formulated three laws of planetary motion, known as Kepler's laws. His first law, the law of ellipses, states that the planets move in elliptical orbits around the sun with the sun at one of the two foci of the ellipse.
Learn more about Johannes Kepler's discovery of the elliptical orbit