Discuss the Working of Planetarium.

A planetarium is a theatre built primarily presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. But instead of a big cinema screen at the front of the room, images are projected onto a domed ceiling of a planetarium to create a more immersive experience. A planetarium can give us an amazing virtual tour of the universe from the earth. The celestial scenes can be created using a wide variety of technology such as a slide projector , video and full dome projector of systems and laser.

Dome: The dominant feature of a planetarium is the large dome. It is defined as the curved surface or hemisphere where the projection is done.

Auditorium: Planetariums have a large room, i.e. auditorium with a dome-shaped ceiling and many seats built to receive the public during a show.

Projector: The most modern planetariums use digital projectors connected to computers. They can project any image onto the dome to show incredible views from anywhere in the universe. Combining data from space agencies, spacecraft and telescopes all over the world, realistic graphical representations of entire galaxies can be projected onto the dome.

A mechanical planetarium forms images of the stars by focusing light from one or more bright lamps through thousands of tiny holes drilled through metal plates. Motion of earth, moon and sun can be projected through separate plate. By means of various sets of gears and electric motors, the planetarium can show the rising and setting of the stars and the motion of the moon and planets along the ecliptic. It can also be used to show the ellipse and simulate the motion of stars on real time basis.

Computer and Software: Computers play the full dome content or scenarios through software. Software with virtual model of the known universe is used for planetarium show.