What if the human eye isn't good enough?
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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.
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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.