Twin Telescopes Promise New Vistas of Universe

If a single telescope gives astronomers another eye with which to peer into the heavens, two new state-of-the-art telescopes just inaugurated on Mt. Graham may open a window on the universe.

One device, an $8-million radio telescope built for Germany’s Max Planck Institute, will look at radiation in the Milky Way and other galaxies seeking the molecular dust and cold gases from which stars are born.

The other, belonging to the Vatican, is a $3-million piece of scientific machinery with a six-foot mirror unprecedented in its precision.

The two telescopes and a third yet to be built comprise the University of Arizona’s Mt. Graham International Observatory, located about 100 miles northeast of Tucson.

The Heinrich Hertz Submillimeter Telescope--that’s the radio telescope--is a joint project with the Bonn-based Max Planck Institute.

The Vatican Advanced Technology Telescope, also a joint university project, continues more than 400 years of star-searching by the seat of Roman Catholicism.

The first Vatican Observatory was built in 1891 on a hill behind St. Peter’s Basilica in Rome. But urban light pollution forced a move in the 1930s to the papal summer residence at Castel Gandolfo, 16 miles away.

Modern light pollution prompted the Vatican scientists’ decision to build a telescope in Arizona. This one will train its unique mirror on the infrared and near-infrared spectrum.

A dedication ceremony on Sept. 18 provoked protests before and during the event by opponents who have long fought construction of the telescopes--both in court and on the mountaintop. Some San Carlos Apaches have argued that the telescopes desecrate sacred ground. Environmentalists have contended that building the telescopes could destroy the forest habitat of the endangered Mt. Graham Red Squirrel, now numbering about 300.

It’s hardly over.

Yet to be built on the mountain is the Large Binocular Telescope, a $60-million device which, with its twin mirrors, each 26.4 feet in diameter, would be among the most powerful in the world.

At an elevation of 10,500 feet, the telescopes afford largely dry conditions essential for both radio and optical astronomy, their operators said.

“It made sense to go there,” said the Rev. Christopher J. Corbally, project scientist for the Vatican telescope.

The Vatican telescope features a lightweight honeycombed mirror made in the University of Arizona’s rotating mirror oven, creating a very short focal length. It was polished to extreme accuracy using a computer and will be air conditioned to minimize temperature changes that distort images.

Corbally said the short, stubby telescope housed inside a short dome will provide wonderfully crisp images.

Most of its astronomers’ work will involve long-term, or survey, projects, which Corbally said “provide the data that are the building blocks of astronomy.”

The Hertz telescope was named for the 19th-Century German physicist who created electromagnetic waves in the laboratory, paving the way for development of radio, television and radar. He also lent his name to hertz, the international unit of frequency equal to one cycle per second.

This telescope resembles a satellite dish, with a parabola-shaped bowl 33 feet in diameter made of carbon-fiber reinforced plastic panels. This latest advance in plastics provides great rigidity to hold the panels’ shape. It’s also impervious to the contraction and expansion of temperature change, said the Hertz telescope’s director, Jacob W. M. Baars.

The radio telescope will study objects only a few degrees above absolute zero, minus 460 degrees Fahrenheit. It will do this by detecting the radio waves emitted by the dense gas and dust clouds in the cold, dark regions of the Milky Way and external galaxies.

Optical telescopes can’t “see” cold matter because the intensity of the radiation it emits is too low.

“A radio telescope looks different from an optical telescope, but we’re really doing the same type of work,” Baars said. “We’re detecting electromagnetic radiation, which is transmitted by objects in the universe.”

Probably the most exciting promise of the radio telescope is its ability to discern star formation and bright quasars, said Roger Angel, University of Arizona Regents Professor of Astronomy and director of the Steward Observatory’s Mirror Laboratory.

“Then we can hope that, like Heinrich Hertz, we’re doing pure research,” Angel said. “Very often, the things that really do prove incredibly useful have come out of pure research.”

Meanwhile, the opposition continues.

Although legislation authorizing the observatory created a 1,700-acre safety zone to protect the endangered squirrels from the public, environmentalists threaten further court battles over the planned third telescope.