"Half-forgotten" sunspot drawings by Renaissance astronomer Johannes Kepler are showing us more about how the sun's cycle of activities work.
Kepler (1571-1630), who was born in what we now call Germany, is best known in astronomy for formulating the laws of planetary motion. His diverse interests, however, included looking at the sun. Drawings he made of a sunspot group in 1607, a new study reveals, show the "tail-end of the solar cycle" with instrumentation before the telescope was more widely available in the early 17th century.
