Astronomers: Galileo Galilei, Mikkola Copernic, carl edward sagan, Russell: henry norris Russell, Yuzhe Zhang, Hubble, Chandraseka, hipparchus. Galileo: Italian mathematician, physicist, astronomer and pioneer of scientific revolution. Mikkola Copernic: Renaissance Polish astronomer, mathematician, doctor of canon law and priest. Carl edward sagan: American astronomer, astrophysicist, cosmologist, science fiction writer, and a very successful popular science writer in astronomy, astrophysics and other natural sciences. Russell henry norris Russell, the founder of Planetary Society, the most influential astronomer in the 20th century, Yuzhe Zhang, a native of Minhou, Fujian, a modern astronomer in China, the discoverer of the "China" asteroid and the founder of modern astronomy in China, Hubble (1889- 1953) is known as the father of galaxy astronomy. Chandraseka: One limit of Chandraseka is enough to make Mr. Chandraseka (19 10- 1995) famous in astronomy. Hipachus (about 190- 120) was an ancient Greek astronomer.