ATOP Hawaii's Mauna Kea volcano, where the air is as clear as Steuben glass, some of the world's most powerful telescopes peer out into space and back toward the beginning of time. Now a new telescope is planned to join the galactic group, which, when linked with a twin, should give unprecedented glimpses of the heavens and enable scientists to see almost to the edge of the universe.
The $93 million Keck II observatory will be a duplicate of the Keck I telescope, the world's largest, now nearing completion on the island of Hawaii. The two scopes, each with a 33-foot mirror, are by themselves designed to be more powerful than any optical telescope on earth.
But when electronically linked, sometime after 1996, they will have eight times the collecting power of the 200-inch Hale Telescope at Palomar Mountain near San Diego, which has dominated land-based optical astronomy since 1947.
Scientists predict a great leap forward for science. Distant galaxies should come into focus that now appear only as wisps.
"The detail these telescopes will be able to discern will be comparable to seeing a car's headlights separately from a distance of 16,000 miles," says Dr. Edward Stone, director of the Jet Propulsion Laboratory and vice president of the California Institute of Technology (Caltech), which will build and operate the telescope in conjunction with the University of California.
Keck II is the latest of a series of major telescopes planned for the 1990s that scientists hope will usher in a "Golden Age" of astronomy. Some of them will observe the heavens from orbit, above the distortions of the atmosphere, like hobbled but functioning Hubble Space Telescope.
Others will peer up from perches on earth. This includes another observatory (8 meters) planned for the rim of extinct Mauna Kea, and an array of telescopes to be built in northern Chile by a consortium of European countries.
'We will have new views'
New instruments will not only expand study of the cosmos through detection of more visible light. Observation will be enhanced all along the electromagnetic spectrum, from radio and infrared to X-ray wavelengths.
"I really think the 1990s will be a Golden Age," says Dr. Sidney Wolff, director of the National Optical Astronomy Observatories in Tuscon, Ariz. "We will have new views along the whole electromagnetic spectrum."
Keck II, like its predecessor, will be funded largely by private money. The W. M. Keck Foundation will put up $74.6 million. Astronomers hope the National Aeronautics and Space Administration will pick up part of the rest.
Also like its twin, Keck II will use a radically new design. Conventional optical telescopes collect light with a single mirror. But grinding one larger than the 200-inch Hale is nearly impossible.
The Keck design gets around this by using a honeycomb of 36 hexagonal mirrors, each aligned by computer. The first tests of Keck I, with nine mirror segments, were finished in November. Scientists say the results warrant going ahead with Keck II.
Some others remain skeptical. One head of a prominent observatory, who requested anonymity, says from what he has seen they "still have a ways to go" to perfect the performance.
Tying the two telescopes together will be difficult. It has long been done in radio astronomy, but optical telescopes have been linked only on a limited scale. Even so, scientists involved with the project say technology will advance over the next few years to make the marriage possible not long after Keck II's scheduled completion, in 1996.
Joining images from the two telescopes, through a technique known as interferometry, would produce dazzling results. The tandem would have the resolution of a scope with a 279-foot mirror.
Looking back in time
The added light-collecting power would help astronomers probe primitive galaxies. For the first time, they might be able to identify planets orbiting the nearest stars. Astronomers, who look back in time by seeing light that has been traveling toward earth, believe they would be able to see the universe as it existed 13 billion years ago - within 2 billion years of the Big Bang that marked its beginning.
The knowledge gained, says Caltech president Thomas Everhart, would "in some measure enrich every individual human being for as long as our civilization survives."