Astronomy is the study of stars and planets. It helps with modern day studies, and it helped in the past as well. Astronomy helped with time, trading, and navigation. The idea was spread throughout Europe during  the 8th to 14th century. It was a collaboration between many philosophers and not just one person. Ptolemy, Aristotle, and Plato were a few of these people. Ptolemy was the main help with the development of astronomy. Philosophers used many of his works to help with new discoveries.