The greatest innovation in astronomy was changing the emphasis of the science from measuring stellar positions for navigation to investigating the physical nature of celestial objects. The first rallying cry to put astronomy to this bold new use came from William Herschel, the maverick astronomer who discovered the seventh planet, Uranus.
At the turn of the nineteenth century, Herschel knew that certain stars varied their brightness and he grew fearful of what might happen to Earth if the Sun suddenly dimmed. He likened the situation to the Egyptians whose fortunes were ruled by the flooding of the Nile. Although the Egyptians could not control this phenomenon, they had developed techniques to predict it and strategies for coping with it.
Herschel thought the same should be true for the Sun and urged his fellow astronomers to adapt their passion for the night sky to understanding the nature of the Sun. Initially, his call to arms fell on deaf ears.
It was finally answered over 50 years later when a gigantic solar flare smothered two thirds of the Earth in a blood-red aurora and blacked-out the global telegraph network. Suddenly, Victorian astronomers realised that they needed to understand the Sun and its effects on Earth. Modern astrophysics began to develop from this point.
Stuart Clark is a science journalist and the author of The Sun Kings (Princeton University Press) (buy this book from Amazon(UK)).