The first detailed photo of the Sun was taken in 1845

The first detailed photograph of the Sun was taken on April 2, 1845, by French physicists Hippolyte Fizeau and Léon Foucault, who captured the solar disk about 4.5 inches across on a daguerreotype plate, showing two groups of sunspots.

Sources split between calling it the first photograph of the Sun and the first detailed one, and the difference is real. According to StarDate, from the University of Texas’s McDonald Observatory, the pair had already taken a series of solar pictures, but on those the Sun was only about half an inch wide and revealed almost no detail. The April 2 plate was the first big enough to show features: the sunspots, the solar limb, and some of the “bumpiness” of the surface. It was later published in a book about astronomy.

The Sun was a late subject. Louis Daguerre’s process dated from 1837, and the Moon had been photographed by 1840. The push came from François Arago, secretary of the French Academy of Sciences, who wanted to know whether photography could improve on hand-drawn records of the Sun. Fizeau had already cut daguerreotype exposures that once took about 30 minutes.

Both men kept working on light. In 1847 they showed that the Sun’s heat rays interfere like waves, and in 1849 Fizeau became the first to measure the speed of light on Earth’s surface. StarDate notes that each man’s figure came within a few percent of the true value.

Compare that with 2020, when the US National Science Foundation’s Inouye Solar Telescope, near the summit of Haleakala on Maui, released the highest-resolution images of the Sun’s surface ever taken. They resolve features as small as 30 km (18 miles) and show the surface broken into churning convection cells, each about the size of Texas: detail the 1845 plate could never hint at.