Becker (2000, par. 1) has defined astronomy as “the science which investigates all the matter-energy in the universe: its distribution, composition, physical states, movements, and evolution”. The University of Oregon (UO, n.d.) identified the origins of astronomy from the earliest written records of the Babylonians in 1600 B.C. The Greeks inherited the records from the Babylonians and used them to design cosmological framework in determining the movements of heavenly bodies.
The first Greek philosopher found to have profound interest in space is Thales. One of his propositions is that “the earth is a flat disc which floats on water” (UO, n.d., par. 3). Eratosthenes used the concept of eclipses in measuring the circumference of the Earth, as shown below:
Another Greek philosopher, Hipparchus “made position measurements of 1080 stars plus sun, moon, and planets which remained the best in existence until the late 1500s” (Astronomy, 2000, par. 8). Heraclides, on the other hand, developed the geocentric solar system model placing the earth in the center of the universe and designing orbits in perfect spheres. (UO, n.d.)
The Greek philosopher and astronomer who was credited for the heliocentric solar system model was Aristarchus. He argued that the sun is the center of the universe and everything else revolves around it.
The contributions of Ptolemy, considered the most influential “Greek astronomers and geographer of his time propounded the geocentric theory that prevailed for 1400 years” (St. Andrews, 1999, par. 1). Ptolemy “compiled a 13-volume summary of Greek astronomy, including star charts, texts on trigonometry, complete information on the Sun and moon (motion, sizes, distances), and, most significantly for later astronomy, an elaborate model for predicting the positions of the planets (using deferents and epicycles) for any time in the future”