Planetariums are continuing to open in Europe and recent years have seen several organizations and meetings devoted to their use. How should a planetarium show be constructed? What are the principles to be followed and the pit-falls to be avoided? This is a problem, because people running planetariums are only rarely astronomers. One great debate centres around the question of whether to use a pre-recorded show or a “live” one.

An automatic show allows a constant level of presentation, however tired or incompetent the lecturer. The Sun rises at the right moment, just as the chosen music starts and either a piece of text or a picture appears. Simultaneous effects can be incorporated, even complicated ones, which often explains a difficult point better.