The contributions of ancient Greek astronomers are numerous. Many of them were also pioneers in mathematics and the origins of scientific inquiry. Some notable examples include Eratosthenes (c. 275–195 B.C.E.), who first made a mathematical measurement of the size of Earth; Aristarchus (c. 310–230 B.C.E.), who first hypothesized that Earth moved around the Sun; Hipparchus (c. 190–120 B.C.E.), who made accurate star charts and calculated the geometry of the sky; and Ptolemy (c. 85–165 C.E.), whose model of the solar system dominated the thinking of Western civilization for more than a thousand years.