From ashes, a return to star-gazing

When a searing brush fire savaged the Canberra region two years ago, it destroyed one of astronomy's crown jewels: the Mt. Stromlo Observatory.

In 20 minutes on this gently rounded mountaintop, the fire incinerated five telescopes and their domes, a historic administration building, a library housing $4 million worth of volumes, and a workshop building cutting-edge custom detectors and optics systems for telescopes around the globe. It was so hot the aluminum on the site burned and brass fittings fused together.

One of the few structures to escape destruction: the visitors' center. "I'd gladly have traded that visitors' center for any telescope on the mountain," says Vince Ford, a research officer at the observatory, driving past soot-blackened shells of buildings.

Now, a little more than two years later, Mt. Stromlo is rising from the ashes. The sounds of power tools reverberate across the summit. And though the observatory isn't laying immediate plans for replacing its research-grade telescopes, officials nevertheless have laid out an ambitious agenda for recovery.

The key parts of their plan: building high-grade astronomical instruments for a new generation of supersized telescopes and mapping - for the first time ever - the entire southern sky.

The recovery here highlights how, despite intense competition among research groups around the world, astronomers and astrophysicists do pull together in the face of disaster.

Here at Mt. Stromlo, workers are busy building new workshops. Facility officials aim to position Mt. Stromlo to become the Stradivarius of astronomical instruments. Australia National University in Canberra, which owns the observatory and its sister facility at Siding Springs, some 335 miles northwest of Sydney, also has begun a small but growing program in designing and building hardware for the business end of telescopes. And, if money allows, officials are considering a new research-class telescope, tentatively dubbed the Phoenix Telescope, for the mountaintop.

Given the changes, "it certainly won't be a carbon copy of the old observatory," says director Penny Sackett.

The pace of recovery draws admiration from astronomers elsewhere.

"Mt. Stromlo was one of the very top research institutions in astrophysics in the world," says Catherine Pilachowski, an astronomy professor at Indiana University in Bloomington. "I've been totally blown away by how successful they've been" at maintaining scientific productivity despite the fire. In 2004, largely through research done since the fire, the observatory's research teams published a record number of results in astronomical journals. "They're just darn good. It may also be that despite the fire, they wanted to show that they weren't beaten down," she adds. "That spirit is an inspiration to everybody."

Some of the credit goes to colleagues around the world, Dr. Pilachowski says. Donations from astronomers and their professional organizations poured in. Researchers scoured their libraries for extra copies of publications, which they bundled up and sent. And observatories worldwide made telescope time available whenever they could to the fire-affected astronomers.

The cornerstone of Mt. Stromlo's renaissance is its digital sky survey and the 1.3-meter telescope the observatory is building for Siding Springs to undertake the cosmic census. The survey is the southern counterpart to the northern hemisphere's Sloan Digital Sky Survey, which aims to map one quarter of the northern sky and gather spectra of the objects it detects. By contrast, the Stromlo Southern Sky Survey aims to cover the whole southern sky six times over three years.

It will leave gathering spectra to other observatories. But it will view the sky though several color filters to give astronomers a rough idea of the makeup of objects the effort will catalog. The telescope is scheduled to get its first glimpse of the sky late next year.

The primary value of this comprehensive survey lies in the foundation it will build for more-detailed studies, notes Mt. Stromlo astronomer Brian Schmidt, who heads the project.

"Surveys are the fundamental building blocks of what we do in astronomy," he says. In the 1700s, for example, the French astronomer Charles Messier mapped "interesting fuzzy things that he kept confusing as comets." That map provided the springboard other astronomers used to study the objects in more detail - objects that turned out to be nebulae, star clusters, and distant galaxies such as the Andromeda galaxy.

Stromlo's survey information - eventually some 75 to 100 terabytes of data, roughly five times the amount of printed information in the US Library of Congress - will become available to astronomers as soon as it is gathered.

"We anticipate that this will be the building block for 50 percent of all the astronomy done in the southern hemisphere for the next decade," Dr. Schmidt says.

Typically, such surveys don't simply map what's known, they uncover new objects, he adds. "There are things out there that go blink in the night, and we don't know they are out there because no one has looked. There will be surprises. There will be some pretty serious science asking fundamental questions" about the galaxy humans inhabit and the larger universe as well.

Ironically, Dr. Sackett says, the observatory had planned the project before the fire. It would have used its old 50-inch Great Melbourne Telescope, which the fire destroyed. But now, astronomers will be able to complete a more thorough survey in a fraction of the time because the new telescope will sit under darker skies at Siding Springs and is designed for the job from the start.

Although modest in size compared with today's 10-meter behemoths, it can take in a much wider patch of the sky than its larger siblings. And it's sensitive enough to record objects a million times as faint as the human eye can detect.

"What's emerging from Stromlo's ashes is really magnificent," says Pilachowski, just back from a meeting of the external advisory board that oversees Stromlo's and Siding Springs' activities. "The fire was devastating, but in some sense it cleared the way for this renewal, which will guarantee Stromlo's place in the future of astronomy."

Although humans have looked up at the stars for millenniums, the view was limited to the naked eye until 1608, when Hans Lippershey invented the first refracting telescope. Galileo improved it a year later, making more discoveries in a single year than all previous astronomers. Since then, technology has quickened the pace of discovery:

• Reflecting telescope: In 1668, Isaac Newton developed the first telescope that incorporated mirrors instead of lenses. This allowed the size of telescopes to expand dramatically, gather more light, and detect fainter objects. The world's largest refracting optical lens measures just under six feet across. The largest reflector, the Keck telescope in Hawaii, measures nearly 33 feet across.

• Radio astronomy: It was discovered almost by accident during the 1930s, when a radio engineer realized that shortwave radio interference came, in part, from the center of the galaxy. With radio telescopes, astronomers soon discovered that many objects emit radio waves, not just light.

• Space telescopes: To study objects at a variety of wavelengths, the United States launched the first space telescope in 1962. The most powerful X-ray telescope was launched in 1999; the most expensive telescope, Hubble, went up in 1990.

Sources: The History of Science and Technology; Encyclopedia of Science and Technology; Guinness Book of World Records 2005