Digital projecting technology opens possibilities for stargazers at Prague Planetarium
Sitting in a cushy blue chair, you see the night sky displayed before you as large as life. The Milky Way cuts across the expanse, and planets zoom in and out to meet your eye. You aren’t a space tourist, just on a visit to the Prague Planetarium with its new digital projection system.
The nearly 25 million Kc ($1.4 million) Sky-Skan Definiti system went live in September.
“We needed to be a digital planetarium,” says Jan Šifner, the Planetarium’s technical director. “It’s better to show things in space, like the constellations, and it’s great to show astronomical events, like the Big Bang.”
The old system, a projector called “Cosmorama,” still lords over the Planetarium’s largest viewing hall. The 2.5 ton machine dominates the center of the large dome. Šifner says they currently only have three shows for the new system, so will keep the old projector until everything has been changed over. Then, they’ll do some cleaning and repairs to the old girl and put her on display.
“It’s wonderful and can’t be thrown away,” Šifner says. The Cosmorama has been in use since 1990, and the Planetarium’s original projector from 1960 is displayed in the building’s foyer.
Differences abound between the old and new systems. Šifner says the digital projector has a 3-D model of space and can compute the positions of stars in real time. With the old system, you could only see the night sky from two positions on earth.
The Prague Planetarium has been showing the stars since 1960. It’s part of the “Observatory and Planetarium of Prague” group, which includes the Štefánik and Záblice observatories. Because of the age of the building, the Sky-Skan Definiti system was one of only two systems that could be installed here.
“It was very difficult to install a new system into an old building,” Šifner says. “We had to find space for cables and pipes for the water cooling system.” They begin the installation process last April, finished in July and made adjustments through September.
Advantages of the new system include the ability to define constellations so they are easily viewed and to change a star’s profile. Stars aren’t really white; each one has its own color, and the new system highlights this.
“We don’t want to show the sky you’ll see when you leave, but astronomical phenomena,” Šifner says.
The Planetarium attracts more than 100,000 stargazers every year. For now, English speakers have the opportunity to view two of the Planetarium’s shows, “Astrology and Alchemy in the Court of Rudolph II” and “The Night Sky.” Headsets with an English translation are available; ask for one when purchasing a ticket. Unfortunately, these shows aren’t available yet on the new system. To see the digital universe in action, check out “Moon Dream,” “Bridge Between the Shores of Time” (about the astronomical history of Charles Bridge) and “Prague Crowned with Stars,” though they as yet are not offered in English translation. Šifner adds that their shows are different than ones that might be shown in Western planetariums.
“Our shows have an old tradition and are stories trying to explain something to people, like comets,” he says. “It’s different from the West, where it is really a ‘show.’ ”
Like the rotation of the earth, future plans keep the Planetarium constantly in motion. Šifner says they plan to have all shows converted to the new system within five years. Other structural changes are in the works over the next two years, including the addition of a coffee shop.
“The planetarium is a time machine, and the new system is a space gate,” Šifner says. “It can move you through space.”