Kepler's cosmological model. Composite image of a model of Kepler's Platonic solids, with Latin text and the title of the work in which this model was described. The German astronomer and mathematician Johannes Kepler (1571-1630) developed this model to demonstrate the relative distances of the planets from the Sun in the Copernican system. This revolutionary new heliocentric (sun-centred) theory, had been published in 1543. Kepler published a supporting work, The Cosmographic Mystery (1597), that put forward the idea that the distances of the six known planets from the Sun were determined by the five regular solids seen here.