This is written by DS12, 7th grade. Writing is right up there with his least favorite subjects . Any feedback appreciated. Thanks
Johannes Kepler studied heliocentricism at his university in the 1590s. Some scientists of the time said the sun was the center of the solar system and this was called heliocentricism. Although most astronomers believed that the Earth was at the center of the solar system and this is called geocentricism.
After his studies, Kepler worked as an assistant to Tycho Brahe. He assisted Brahe in studying the movement of the planets. They could not answer the question of why Mars seemed to move at different speeds. Before Brahe died in 1601, he asked Kepler to continue his work.
Several years later, Kepler hypothesized that Mars orbit must be an ellipse. He then put forth Kepler’s First Law of Planetary Motion which stated “Planets move in elliptical orbits, sun is one focal point”. He published his findings in Astronomia Nova in 1609.