The Mesopotamians are thought to be among the first astronomers to walk the planet. They recorded star patterns by writing on wet clay, then letting it dry. Although they may have not been the first to observe the stars, there is evidence that they were the first to write down their observations.
The Egyptians went into further detail when studying the stars. By taking measurements of the stars alignment in the sky, they built temples as well as pyramids that aligned in a certain way. Their buildings each lined up with the directions North, East, South, and West. They also used stars to predict the annual flooding of the Nile river.
Ptolemy was a geographer, astronomer, and astrologer who considered Earth to be the center of the universe. He had the same idea as Aristotle and many other astronomers of his time. He created a geocentric modal of out solar system.
Contrary to popular belief at the time, Nicolaus Copernicus believed that the sun was the center of the universe, rather than earth. This idea was known as the Heliocentric theory. He also believed that Earth revolved around the sun while also spinning on an axis.