A planetarium is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation.
A dominant feature of most planetariums is the large dome-shaped projection screen onto which scenes of stars, planets and other celestial objects can be made to appear and move realistically to simulate the complex 'motions of the heavens'.
The celestial scenes can be created using a wide variety of technologies, for example precision-engineered 'star balls' that combine optical and electro-mechanical technology, slide projector, video and fulldome projector systems, and lasers. Whatever technologies are used, the objective is normally to link them together to provide an accurate relative motion of the sky.
Typical systems can be set to display the sky at any point in time, past or present, and often to show the night sky as it would appear from any point of latitude on Earth.
The plural of planetarium can be either planetariums or planetaria.The term planetarium is sometimes used generically to describe other devices which illustrate the solar system, such as a computer simulation or an orrery.
The term planetarian is used to describe a member of the professional staff of a planetarium.Planetarium software refers to a software application that renders a three dimensional image of the sky onto a two dimensional computer screen.
Planetariums have become well-nigh ubiquitous, with some privately owned. A rough estimate is that in the United States there is one planetarium per 100,000 population, ranging in size from the Hayden Planetarium's 20-meter dome seating 430 people, to three-meter inflatable portable domes where children sit on the floor.
Such portable planetariums serve education programs outside of the permanent installations of museums and science centers.
For those that want to bring a little of the Universe into their home, there are a number of home planetariums that are both educational and that make great gifts.
Adler Planetarium Founded in 1930 by Chicago business leader Max Adler, the museum is home to three full-size theaters.
Fleischmann Planetarium Built in 1964 and originally called the “Fleischmann Atmospherium-Planetarium,” it was the first planetarium in the world to project full-dome movies.
Morehead Planetarium Since 1949, the Star Theater has been a giant classroom for students, teachers, school groups, senior citizens, youth groups and the general public.
Peter Harrison Planetarium The Peter Harrison Planetarium is part of the Royal Observatory complex in Greenwich Park London England.
Schenectady Planetarium See 8,500 stars, 26 deep sky objects, 24 constellations, and much more! View the sky from any location on Earth and any place in the solar system!