We learn more about the final frontier every day, but the technology that allows us to probe the cosmos did not appear spontaneously. This list recognizes some of the greatest individual contributors to space exploration and our knowledge of the universe. I have ordered this list chronologically.
10
Claudius Ptolemy
90-168
Ptolemy was one of the first astronomers. He developed one of the earliest known models of the universe based on his observations of the night sky. His model placed earth at the center of several “celestial spheres” to which the sun, stars, and other planets were fixed. His model was one of the first to account for the “wandering” of the planets in the night sky. His astronomical treatises the Almagest and the Tetrabiblos cataloged 48 constellations and provided a table for astronomical predictions that were used by future astronomers. The work of Ptolemy formed the basis of astronomy for more than a thousand years.
