Magic under the dome.
"Sit back, relax, and enjoy the show."
With this phrase, millions of visitors are welcomed each year to planetariums around the world. In the past, many patrons took these words quite literally; they sat back, relaxed, and promptly dozed off even as the light faded and the program began. Today, new technology and innovative programming are helping revitalize star theaters and, in the process, are radically altering the programs that audiences see in these domed environments.
The Planetarium Is Born
The word planetarium usually refers to either the domed theater in which stars are displayed on the ceiling or the instrument used to project those stars. Although the modern planetarium was born a mere 80 years ago, its lineage dates back two millennia and ultimately is due to the marriage of two disparate pieces of historical technology: star globes and orreries.
The Greek mathematician Archimedes is often credited with inventing, in the 2nd century BC, a device that illustrated the motions of the planets, the Sun, and the Moon, though the mechanism is known only through an unconfirmed, secondhand account. More common during this era were Greek and Roman celestial spheres with constellations painted or engraved, in reverse, on their exteriors. But to see the constellations as they actually appear in the sky, the viewer would somehow have to crawl inside one of these little globes to look up and out.
In 1664 Andreas Busch of Limberg, Germany, constructed a sphere that let a dozen people at a time do just that. The three-ton, 11-foot-diameter hollow Gottorp Globe had stars and constellations painted on its inner surface, which was illuminated by candles. Turning a handle made the sphere rotate, causing the "night sky" to slowly spin around the spectators seated inside.
While some craftsmen tried to mimic the night sky's appearance, others sought to replicate planetary motion. London instrument maker George Graham constructed a mechanical model of the Sun-Earth-Moon system sometime between 1704 and 1709. The device, later dubbed an "orrery," was soon expanded to include the naked-eye planets and became popular for both entertainment and educational purposes.
Early in the 20th century, German astronomer Max Wolf and Oskar von Miller of the Deutsches Museum in Munich, Germany, began discussing how to simultaneously display the night sky, the planets, and their motions. Von Miller turned to the Carl Zeiss optical company in Jena for help. Shortly after World War I ended, Zeiss's chief engineer, Walter Bauersfeld, realized that optical projection was the answer: "The great sphere shall be fixed, its inner white surface shall serve as the projection surface for many small projectors which shall be placed in the center of the sphere."
In August 1923 the first star projector --the Zeiss Model I--was installed in a temporary dome on the roof of the Zeiss factory in Jena. When its 4,500 artificial stars illuminated the blackened theater, it was immediately christened "the Wonder of Jena." Later the Model I was moved to the Deutsches Museum, and on October 21, 1923, Bauersfeld gave the first official public planetarium show to an enthusiastic audience.
A Planetarium Building Boom
The planetarium impressed both the citizens of Germany and civic leaders around the world, many of whom wanted this "scientific marvel" for their cities. In 1927 the first planetarium outside Germany opened in Vienna, Austria. The first major star theater constructed in the Western Hemisphere was Chicago's Adler Planetarium, inaugurated on May 10, 1930, with a Zeiss Mark II installed in a 65-foot dome. Others soon followed, including the Fels Planetarium in Philadelphia (November 1933), Griffith Observatory in Los Angeles (May 1935), New York's Hayden Planetarium (October 1935), and Pittsburgh's Buhl Planetarium (October 1939). The 1930s also saw the construction of non-Zeiss star machines, though all were one-of-a-kind instruments until American Armand Spitz began marketing his Model A pinhole projector in 1947.
As planetariums grew in number and popularity, the presentations in these facilities became more visually elaborate. Special effects and single-image slide projectors were added to help explain eclipses, comets, meteors, and other astronomical phenomena. Still, the shows remained little more than illustrated lectures under the stars.
When Sputnik launched the Space Age in 1957, it sparked a renewed emphasis on science education in the US. One consequence was a planetarium building boom. Hundreds of universities, colleges, and even high schools erected 20- to 30-foot-diameter domed theaters on their campuses, while many museums and science centers added larger planetariums to their facilities. Innovative theater designs such as sloped floors and hoist-mounted star projectors appeared, and two Japanese companies--Goto Optical and Minolta--began challenging the dominance of Zeiss and Spitz by selling star machines in North America.
While planetariums multiplied, the shows presented in them began evolving. Program content and presentation style were significantly altered by the addition of complex special effects, multiple-image slide projectors, and automation systems to control all these devices. Live lectures gave way to prerecorded narration. More significantly, the night sky was no longer the focus. Programs became spectacles, dealing with topics far beyond star and constellation identification. Some planetarium professionals decried the change, but others argued that well-produced shows reinforced the drama of the universe that planetariums were attempting to portray. Audiences responded enthusiastically, and attendance soared.
The popularity of domed theaters soon attracted nonastronomical programming, often to the detriment of the star shows. In November 1973, a company called Laserium set patterns of laser light dancing to rock music at Griffith Observatory. "Laser mania" swept the planetarium community, and revenue-generating laser-light extravaganzas began supplanting science shows. That same year OMNIMAX, a domed-theater version of IMAX's popular large-format film-projection system, was unveiled at the Reuben H. Fleet Space Theater in San Diego. The astronomy show now faced serious competition in its own home, and it was not faring well.
Outside forces also began eroding star-show attendance. Even before the final Moon landing in 1972, interest in space was waning. The movie Star Wars, released in 1977, took special effects to an astounding level, leaving star theaters, with their inexpensive, homemade effects, looking worn and amateurish. And, according to planetarium consultant Ian McLennan, "Science-themed, leisure-time options for families were on the rise. The star theater was no longer the only game in town."
As the 1970s gave way to the '80s, astronomy-show attendance slumped and revenues declined. It was clear to some in the planetarium community that domed theaters had to either respond to changing expectations by reinventing themselves or face the possibility that they would soon become irrelevant and fade away.
Welcome to the Digital Domain
A blood-red sun sets, twilight fades, and stars begin to emerge--except they don't form the familiar constellations of Earth. Three tiny moons feebly illuminate distant, roiling clouds. Nearby, several translucent creatures float past, their shapes oddly reminiscent of upside-down maple trees, complete with roots. The wind stirs, the clouds begin to dissipate, and another sun--this one blazing white--climbs into view, its light revealing an alien landscape far below.
Welcome to the new planetarium, a digital domain of dome-filling imagery that plunges audiences into moving, three-dimensional vistas unlike anything previously seen in a star theater. Known as "all-dome" or "immersive video," this is the latest tool in an industry constantly seeking imaginative ways to portray the wonders of the universe.
All-dome imagery started modestly in the late 1970s when individual video projectors began appearing in star theaters. Video images of rotating planets, spinning galaxies, and other celestial sights could be made to float among the stars. Although small, these video clips greatly enhanced programming by replacing static slides with moving imagery.
In 1983 Evans & Sutherland installed the first digital star projector at the Science Museum of Virginia in Richmond. Digistar I used a fisheye lens, positioned above a monochrome screen, to magnify a computer-generated star field and focus it on the dome. Critics assailed the blobby, green appearance of its stars, but Digistar I had several advantages over its optomechanical rivals. For example, it could tap into its database of more than 6,700 stars to accurately portray the sky from any location within 650 light-years of the Sun or replicate thousands of years of proper motion of the stars in Earth's sky.
Combining digital star fields with multiple video images that seamlessly covered the entire dome was the logical next step. In May 1997 Goto Optical debuted Virtuarium, the first all-dome digital system in a planetarium in Minamimakimura village, Japan. Other companies soon premiered their own immersive systems (see the box on the facing page), and currently more than 60 theaters worldwide offer shows in an all-dome format.
Playing a leading role in this digital revolution is New York City's Hayden Planetarium (S&T: May 2000, page 46). Powering the new Hayden are a Zeiss Mark IX, which employs fiber-optic technology to project 9,100 stars, and a Silicon Graphics Onyx2 supercomputer that generates the dome-filling scenes, some of which are based on real positional data of millions of stars and galaxies. Hayden's programs are big budget, with big names attached (Tom Hanks and Harrison Ford narrated the first two shows). But these shows are also available, at a reasonable price, to any other planetarium with immersive-video capability.
Every immersive theater can project dome-filling video, but there are differences between facilities. All can play back prerecorded, high-definition digital video shows whose visual quality rivals that of any other medium. But some theaters also employ a real-time digital system, based on flight-simulator technology, to generate scenes "on the fly." In some cases the show presenter uses a joystick to direct flights through a digital universe; at other times the audience guides the journey as the system responds to input from feedback buttons in the armrest of each chair.
The recently opened Clark Planetarium, a facility that replaces the venerable Hansen Planetarium in Salt Lake City, Utah, is the ultimate digital theater. No slide or special-effects projectors inhabit the mechanical areas behind the dome, and no star projector, digital or otherwise, lurks in the center of the theater. To Aaron McEuen, Clark Planetarium's producer and lead animator, digital technology means freedom. "As a producer for this medium, I find that the phrase 'the sky is the limit' does not apply," says McEuen. "We can now visualize, on the dome, anything that can be imagined. An immersive theater is also an educational tool that is unchallenged in its capabilities, because with it we can reveal the secrets of both outer and inner space."
Don't think this digital world is only for big domes--immersive technology is already at home in small theaters. In fact, affordable single-projector, all-dome systems could be the key to survival for small, aging planetariums in schools, colleges, and universities. Gary Meibaum runs a 20-foot-diameter theater in the St. Charles Parish Library in Luling, Louisiana. He recently replaced his 25-year-old star machine and numerous homemade special-effects projectors with a Minolta Mediaglobe. A one-person operation, Meibaum appreciates the speed with which he can now create shows. "It's great," he says. "If I can see it on my computer monitor, I can get it on the dome." He doesn't mourn the loss of those finicky effects projectors.
Whether the theater is large or small, an all-dome system can replace not only a mechanical star machine but also individual video projectors, dozens of slide projectors, and the (sometimes) hundreds of special effects that inhabit most existing planetariums. The drawback is that it can be more costly to produce a high-quality, 30-minute digital show than to create a similar program using "old-fashioned" planetarium technology. Sensing an opportunity, numerous vendors (including the manufacturers of immersive systems) have begun producing all-dome shows, though they tend to be broad-topic, generic programs that can be challenging to customize to the needs of each facility.
In the end, the success of the digital theater will depend on the same formula that works for other leisure-time attractions--a first-class product and strong marketing. Technology, by itself, is not enough. "Some planetariums are looking to all-dome video as a guarantee of success," says Bill Gutsch, former chairman of the American Museum-Hayden Planetarium and now president of Great Ideas, a company that provides consulting and production services to science centers and others. "Immersive video is exciting and has great potential, but creativity will still be the most critical factor in success, not hardware."
It's in the Way That You Use It
Of course, not all star theaters can afford the latest and greatest in digital technology; some don't even want it. In 2002 Kent Montgomery, director of Rollins Planetarium at Young Harris College in Georgia, received funding to replace the old Spitz 512 star projector housed in its 40-foot dome. He looked carefully at both optomechanical and digital star projectors.
"Since our theater is used for teaching college astronomy classes as well as planetarium shows, I realized early on that I wanted to get the best possible star field I could, because I'm trying to provide a quality educational experience." he says. Ultimately he selected a nondigital instrument--the Chronos star projector from Goto Optical. Still, Montgomery recognizes the potential of the digital realm. "I hope to add an all-dome video system to our planetarium someday so I can have the best of both worlds."
Many planetariums are using their old-fashioned technology in new ways. Some incorporate laser projection into their public shows; others feature live actors who interact not only with the audience but also with video characters projected on the dome. Still other facilities behave more like businesses than not-for-profit organizations by forming partnerships and consortia to produce quality programs at affordable prices.
Then there are those who believe their audiences respond best to live shows where the night sky is still the "star" attraction. Griffith Observatory, currently undergoing an $83 million renovation, will continue its tradition of live programming when it reopens in late 2005. The theater will have plenty of new equipment (including a Zeiss Mark IX star projector and a full-dome laser system), but director Ed Krupp declares, "These technological wonders are tools to accomplish our storytelling goals. Griffith ... will not present prerecorded 'movies' in the planetarium theater."
Planetariums on the Rebound?
In Ian McLennan's view, "Planetariums are best suited to inspire and make people think." Those working in immersive theaters concur, maintaining that the new technology is merely a tool to help do just that. Others, lacking the latest gadgets, concentrate on telling the story of astronomy in an entertaining manner, avoiding the dry recitation of facts that was the staple of star shows in years past. But can all this reverse the negative perception of planetariums that arose during the final two decades of the 20th century? It is still too soon to tell, but some trends are encouraging.
Each year an estimated 90 million people attend shows at nearly 3,000 planetariums in 93 countries. Admittedly, these impressive numbers must be viewed with caution, since they are based on an informal survey that cannot accurately reveal if the global audience level is rising or falling. But anecdotal evidence suggests that the initial surge of high attendance that inevitably accompanies the opening of a new or refurbished theater is stronger these days, and lasts longer, than in the past.
Star theaters are springing up everywhere--from an oceangoing liner (the Queen Mary II) to the 23rd floor of a skyscraper (in Koriyama City Science Center, Japan). And the technology continues to evolve. Even as all-dome systems for small theaters improve, dome-filling, high-definition laser imagery from digital sources is ready to replace video projection in large facilities.
Ever since the Wonder of Jena created a dome full of stars, the planetarium has developed, and retained, a certain cachet based on an odd-looking projector, an unusual theater configuration, and a subject matter that is literally "out of this world." The oohs and aahs emanating from today's audiences as the lights dim and the stars emerge confirms that there still is magic under the dome, whether in a small school planetarium or a large public theater. Indeed, the words of astronomer Elis Stromgren, commenting on the world's first planetarium in 1923, still ring true for today's domes with their immersive technology:
Never before was an instrument created
which is so instructive as this; never before,
one so bewitching; and never before
did an instrument speak so directly
to the beholder.... The planetarium is
school, theater, and cinema in one,
under the eternal dome of the sky.
All-Dome Video: THE MAJOR PLAYERS
Unlike movie theaters, not all immersive theaters are the same. The six companies involved in manufacturing all-dome systems create a variety of products aimed at different types of facilities. Some of this new technology might be coming to (or may already be in) a dome near you.
Evans & Sutherland (Salt Lake City, UT)
Digistar 3 (and the single-projector version, Digistar 3 SP) is an integrated all-dome digital system that can simultaneously project high-definition, pre-rendered digital video, real-time 3-D computer graphics, and star fields. E&S is developing a laser-projection unit to replace the video projectors currently used to display its all-dome imagery.
Carl Zeiss Jena (Germany)
Zeiss's All-Dome Laser Image Projection (ADLIP) system can replace the video projectors currently needed to place immersive-video images on the dome; ADLIP is compatible with Sky-Skan and Spitz systems.
Goto Optical Mfg. Co. (Japan)
The latest incarnation of the Virtuarium for large theaters is powered by Evans & Sutherland's Digistar 3.
Minolta Planetarium Co. (Japan)
Mediaglobe is a complete all-dome video-projection playback system designed for small theaters. Skymax is for large domes and uses Sky-Skan's SkyVision system.
Sky-Skan, Inc. (Nashua, NH)
SkyVision plays pre-rendered image sequences and movies and can be combined with DigitalSky, a system that generates real-time star fields and astronomical special effects. definiti PD is a new single-projector unit designed for portable domes.
Spitz, Inc. (Chadds Ford, PA)
ElectricSky I is a multi-projector video-projection system available in partial- and full-dome configurations, while ElectricSky II uses a single (or dual) projector, located in the center of the theater, to create all-dome environments. SciDome is a digital projection system for small theaters.
A Dome with No Home
Some of the world's most popular planetariums are not brick-and-mortar installations with hundreds of seats. They are portable planetariums--small domes that bring the night sky to schools and communities that lack their own star theaters and are too far away from a large planetarium for regular visits.
In 1977, inspired by the enthusiastic response of his seventh- and eighth-graders to a trip to the planetarium at the Boston Museum of Science, Massachusetts middle-school teacher Philip Sadler developed a 16-foot-diameter inflatable fabric dome and a star projector that uses interchangeable cylinders to show the night sky. So great was the demand for his temporary star theater that Sadler quit teaching, started Learning Technologies, Inc., and began manufacturing Starlab, the first commercially available portable planetarium.
Today, Starlabs around the world host more than 12 million adults and children annually. Other companies now manufacture portable domes, and what started as a project to help teachers and students discover astronomy has blossomed into a worldwide network of users bringing the stars to the people.
New Stars for Baton Rouge
Louisiana's first major public planetarium opened in May 1967 at the Louisiana Arts and Science Museum (LASM) in Baton Rouge, with a 60-foot dome and a Zeiss Model IV star projector. Twenty-one years later, concerns about its electrical system and the discovery of asbestos insulation resulted in the facility's closure and eventual demolition. Its replacement has been a long time coming.
According to Carol Gikas, executive director of LASM, the delay between closing the original facility and opening the new one last May was due to economics, not indifference to the idea of a new planetarium. "Even though the planetarium was closed, people called us almost every day to ask, 'What are your shows?' or 'When are you open?' That went on for a decade, so there was certainly great interest in the community."
In 1997 a capital campaign was launched that ultimately raised $17 million, and after 24 months of construction, the Irene W. Pennington Planetarium and ExxonMobil Space Theater opened. While built as a multi-purpose facility, "it's first and foremost a planetarium," says Gikas. The second-floor theater has a 60-foot dome with 148 seats, a Minolta Infinium II star projector, a Sky-Skan all-dome video system, an Omniscan laser-projection system, and a MegaDome 70-millimeter large-format film projector. On the ground floor is a new astronomy exhibit gallery. Scale models of the planets grace the tower through which audiences exit the space theater.
Although LASM was wildly popular when the new planetarium opened (50,000 visitors during the first month alone, compared to 55,000 during the previous 12 months), Gikas knows that attendance will settle in at a lower level, and that LASM will face the same funding challenges as every other facility with a planetarium. But that $17 million includes an endowment, something Gikas says is critical. "I didn't want to be back in the situation we were in during the 1980s, when we were continually struggling to offer a product and upgrade the equipment. I just didn't want to be in the same boat 10 years from now."
Associate editor PAUL DEANS spent three decades writing, directing, and presenting shows in various star theaters across Canada before joining Sky & Telescope.
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|Publication:||Sky & Telescope|
|Date:||Jan 1, 2004|
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