Copernicus and Ptolemy Astronomy is one of the oldest sciences. Two of the greatest astronomers of all time are Claudius Ptolemy and Nicolaus Copernicus. These men had very different ideas and theories. Claudius Ptolemy was born around 100 A.D. and died around 165 A.D. He was considered one of the greatest Greek astronomers and geographers of ancient times. Very little is known about him, but he did his observations of astronomy in Alexandria, Egypt. His …showed first 75 words of 388 total…

…showed last 75 words of 388 total…we cannot see the movement because we are on earth. He also said that all the planets are moving in orbits and revolving around the sun. The earth spins around its axis once a day. He believed that a planet moves faster if it is near the sun and in a small orbit. Copernicus could not prove his own theory, but it was later proven to be correct. This is when modern day astronomy began.