Fizeau and Foucault took the first detailed photograph of the Sun

On April 2, 1845, French physicists Hippolyte Fizeau and Léon Foucault made what is regarded as the first photograph of the Sun. Working at the prompting of astronomer François Arago, who wanted to test whether the new art of photography could record the heavens, the pair turned their daguerreotype apparatus toward the solar disk.

Photographing the Sun was no small feat. Its brilliance demanded a vanishingly brief exposure, and Fizeau had already refined the daguerreotype process, cutting exposure times that once ran to half an hour. Their image, about five inches across, captured the Sun’s edge and even a scattering of sunspots.

The plate showed the solar limb and sunspots — the Sun’s blemishes recorded for the first time.

The result opened the field of solar photography, giving astronomers a way to document the Sun’s changing face rather than rely on sketches by hand.