-
He calculated the circumference of Earth. This is an important discovery because it allows for the same methods to be used to discover the size of all planets.
-
He positioned where the moon, sun, earth, Venus, and Mercury were. This is important because it set up a map for astronomers.
-
He discovered that planets orbit around the sun. This is important because it explains why the sun rises and sets at different time on earth, and also set up future knowledge of categorizing solar systems.
-
He discovered a supernova. This discovery is important because it allowed for more discovery of the solar system.
-
He discovered the planets move in elliptical motions. This is important because it tells astronomers how our solar system works.
-
He discovered gravity. This is important because it explains why all things move the way that they do.
-
He discovered the theory of relativity. This is important because it explains the origin of the universe.