Noon approached on September 1, 1859, and British astronomer Richard Christopher Carrington was busy with his favorite pastime: tracking sunspots, those huge regions of the star darkened by shifts in its magnetic field. He projected the Sun’s image from his viewing device onto a plate of glass stained a “pale straw colour,” which gave him a picture of the fiery globe one inch shy of a foot in diameter.
The morning’s work went as normal. Carrington patiently counted and charted spots, time-lining changes in their positions with a chronometer. Then he saw something unusual.