Ever since humans figured out how to walk on two legs, we have looked to the cosmos and wondered what celestial objects illuminate our night skies and how we all fit into it. The Greek polymath Eratosthenes, for example, was the first person to calculate the circumference and axial tilt of Earth. Nicolaus Copernicus created one of the first models of the universe that was sun-centric instead of Earth-centric, and many years later, Edwin Hubble established both the fields of extragalactic astronomy and observational cosmology before his name got plastered onto a space telescope. While scientists hold these early pioneers in astronomy in high regard, their once earth-shattering observations no longer answer our burning questions about the mysteries of outer space, at least until recently. An international collaborative group led by Nagoya University in Japan is using sketches of the sun made by fellow space telescope user Johannes Kepler to understand the history of our great heat lamp. Specifically, the team is trying to resolve a controversy regarding the duration of solar cycles at the beginning of the 17th century, which are associated with the transition from regular solar cycles to the Maunder minimum: a unique, grand solar minimum in observational history during which fewer than 50 sunspots occurred within a 28-day period. For those who aren’t astronomers, normal cycles with that time span show between 40,000 and 50,000 sunspots. Johannes Kepler’s 1607 sunspot sketches. Courtesy of Nagoya University and iStock.com/sapannpix. The sketches were created in 1607 with the use of a camera obscura, which is the fancy post-Renaissance name for a small hole in a wall that can project the sun’s image onto a piece of paper. While the father of modern optics surely started in humble places, Kepler’s sketches of the camera obscura image led to the discovery of sunspot clusters on the sun’s surface. These areas exhibit such intense magnetic activity that they appear as darker blemishes. Beauty spots aside, the sketches are important to the researchers, marking some of the earliest datable instrumental records of solar activity in the early 17th century. They even predate telescopic sunspot drawings by about three years. The year that Kepler made his drawings was between solar cycles on the way to the Maunder minimum, which tells researchers how the sunspots’ gradual decrease in visibility depends on the solar cycle. After running their tests, the researchers determined that Kepler’s sunspots seemed to appear at the end of the previous solar cycle, suggesting a normal cycle duration and proving a few scientists’ theories wrong in the process. The researchers find this fascinating, and not only because a 17th century genius continues to prove people wrong; the results also show that this part of the sun’s history could inform us of its future, as well as how solar activity affects Earth. The research was published in Astrophysical Journal Letters (www.doi.org/10.3847/2041-8213/ad57c9).