1839

First Astrophotographs

John William Draper (1811–1882), Henry Draper (1837–1882)

Most successful pre-nineteenth-century astronomers were also talented artists by necessity, because the only way for them to record their observations was to sketch, draw, or paint what they saw with their eyes. With the invention of photography in 1839, however, the situation quickly changed. Over time, new and improved methods of taking photographs would forever revolutionize astronomy.

Early photographic methods were cumbersome, crude, and dangerous. The daguerreotype process, invented by the French inventors and artists Louis Daguerre and Joseph Niépce, could create relatively sharp images on wet copper plates coated with silver, but the process required photographers to work closely with toxic vapors of mercury, iodine, or bromine. Still, the results were impressive, and the French government made the process publicly available to the world for free very soon after its invention.

The American doctor, chemist, and photographer John William Draper was quick to develop some improvements on Daguerre’s process. His scientific interests compelled him to point his equipment skyward, and he took a series of increasingly higher quality daguerreotype plates of the Moon from 1839 through 1843. Draper’s lunar plates were the first recorded photos of a recognizable astronomical object; thus he is hailed as the inventor of astrophotography.

The invention of dry plate technology in the 1870s helped astrophotography become an important scientific research tool for the recording of images as well as spectra. John Draper’s son Henry Draper continued his father’s legacy in astrophotography by mounting his cameras to large telescopes and recording the first photographic spectrum of the star Vega in 1872, as well as acquiring the first photograph of the Orion Nebula in 1880.

Film eventually replaced plates, but analog photo technology reached its limit of sensitivity in the mid-twentieth century. Electronic imaging technology (mainly the Charge-Coupled Device) was developed in the 1970s and has now taken over as the photographic medium of choice for both scientific and consumer uses.

One of the first known astronomical photographs of any kind, from a daguerreotype plate of the nearly full Moon taken by John William Draper in the winter of 1839–1840 from New York City. Draper focused the Moon’s image onto the silvered copper plate using a 3-inch (7.6-centimeter) lens, and had to keep the image stable on the same part of the plate for nearly 20 minutes.