Johannes Kepler thought he sketched Mercury orbiting across the sun. What he actually captured has solved a solar mystery

German astronomer Johannes Kepler’s sketches of sunspots in 1607 are providing insights into solar activity in the 17th century. Kepler’s drawings, which were previously overlooked, are helping scientists understand the variability of the sun over time and its changes. A recent study recreating the circumstances during which Kepler made his sketches revealed that they predate existing telescopic sunspot records. This finding contributes to our understanding of the sun’s behavior and its transition into extended periods of weakened activity. Analyzing historical solar records is essential for studying solar cycles and events like the Maunder Minimum.