De revolutionibus orbium coelestium Earth's axis rigidly to a Sun-centered sphere. The unfortunate consequence was that the terrestrial rotation axis then maintained the same inclination with respect to the Sun as the sphere turned, eliminating the seasons." To explain the seasons, he had to propose a third motion, "an annual contrary conical sweep of the terrestrial axis". It was not until the Great Comet of 1577, which moved as if there were no spheres to crash through, that the idea was challenged. In 1609, Kepler fixed Copernicus' theory by stating that the planets orbit the sun not in circles, but ellipses. Only after Kepler's
The Sun in culture The Sun in culture The Sun, as the source of energy and light for life on earth has been a central object in culture and religion since prehistory. Ritual solar worship has given rise to solar deities in theistic traditions throughout the world, and solar symbolism is ubiquitous. Apart from its immediate connection to light and warmth, the sun is also important in timekeeping as the main indicator of the day and the year. The earliest understanding of the Sun was that of a disk in the sky, whose presence above the horizon creates day and whose absence causes night.