Solar system model. Engraving of a woman astronomer or astrologist holding an instructional model of the Copernican view of the solar system. The Sun is represented by a small, solid sphere at the centre of the device. The horizontal bands in the framework around the Sun represent the orbits of the planets of the solar system. This system was first proposed by Nicolas Copernicus (1473- 1543) in 1543. Engraving of a 16th century model. During this period, observations of heavenly bodies were used as much for astrology as astronomy.