What if the human eye isn't good enough?
The development of photography created a revolution in astronomy. But over the past decades electronic detectors have taken over. They ensure almost no single photon gets lost.
For some three centuries after the invention of the telescope, all observations were done by eye and recorded in notebooks. From the end of the 19th century, photography became a powerful new tool for astronomers: photographic plates could collect light over a long exposure time and reveal much fainter objects. Moreover, photography was much more objective. With the advent of charge-coupled devices (CCDs – the same detectors used in everyday digital cameras), astronomical detection techniques became more powerful than ever: CCDs are much more sensitive than the human eye.
How well can you hear and see? A sensitive microphone can pick up sounds your ears can’t hear. In the same way, electronic detectors are much better at catching light than your own eyes.