Special: From Silver to Silicon

In this new Hubblecast episode, Dr. J guides us through the fourth chapter of Eyes on the Skies, the International Astronomical Union's movie celebrating the telescope on its 400th anniversary in 2009. Observing the Universe through the eyepiece of a telescope is one thing, but recording the observations for posterity is something quite different. Originally astronomers used pen and paper to draw what they saw, but the human eye is a lousy detector and our brain can play tricks on us. Astrophotography, first explored in the mid-nineteenth century, has proved to be a powerful, objective way of recording telescopic images with the advantage that long exposures revealed much more than the eye could ever see. But the true revolution arrived with electronic detectors and digital image processing.