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
Earth, Moon, and Planets Earth, Moon, and Planets Earth, Moon, and Planets is a peer-reviewed scientific journal, published approximately ten times per year by Springer Science+Business Media. It was established in 1969 under the title "The Moon", was known as "The Moon and the Planets" from 1978 to 1983, and was first published under the current title in February 1984. The editor-in-chief is Murthy S. Gudipati (Caltech and JPL). The journal's main focus is on research about the Solar System. Besides original research articles, "Earth, Moon, and Planets" publishes conference proceedings, review articles, book reviews, and special issues. "Earth, Moon, and Planets" focuses on