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
Myth of the flat Earth flat Earth. The widely circulated engraving of a man poking his head through the firmament surrounding the Earth to view the Empyrean, executed in the style of the 16th century, was published in Camille Flammarion's "L'Atmosphère: Météorologie Populaire" (Paris, 1888, p. 163). The engraving illustrates the statement in the text that a medieval missionary claimed that "he reached the horizon where the Earth and the heavens met". In its original form, the engraving included a decorative border that places it in the 19th century. In later publications, some of which claimed that the engraving dates to the 16th century, the