Johannes Kepler (1571-1630) was one of the most admired astronomers who ever lived and a key figure in the scientific revolution. A defender of Copernicus' s sun-centered universe, he famously discovered that planets move in ellipses, and defined the three laws of planetary motion. Perhaps less well known is that in 1615, when Kepler was at the height of his career, his widowed mother Katharina was accused of witchcraft. The proceedings led to a criminal...