Share this story
Close X
Switch to Desktop Site

New Optics Get Stellar Reviews

IN a room of blinking computers next to where one of the world's most-famous telescopes scans the starry night, Chris Shelton and Sallie Baliunas are making astronomical history.

With the click of a computer mouse, the fist-size ball of fuzzy light on their screen metamorphoses into an intense white dot.

About these ads

The unprecedentedly crisp stellar image is the product of a new set of high-tech optics fitted to a World War I vintage telescope. The technology promises to revolutionize earthbound astronomy by removing the atmospheric distortions that have troubled serious stargazers since the days of Galileo.

''We have de-twinkled the star,'' says Ms. Baliunas, director of science programs for the Mt. Wilson Institute.

No other telescope on Earth can provide sharper cosmic images, say scientists here, now that the 80-year-old Hooker Telescope is equipped with ''adaptive optics'' technology.

By essentially removing the visual turbulence caused by atmospheric heat, the set of mirrors, fiber-optic cables, and computers is capable of helping this 100-inch telescope create images of stars now 50 times brighter than before the retrofit.

''They're as sharp as the images from the Hubble Telescope,'' says Robert Jastrow, director of the Mt. Wilson Institute. ''That's saying a lot because of the Hubble's incredible cost [$1 billion] and its advantage of being in the blackness of space.''

For a fraction of that cost ($900,000), and with the operating ease of solid ground, earthbound astronomers will now be able to scrutinize celestial bodies with a breathtaking clarity they have heretofore only dreamed of. Scientists say the magnifying power is strong enough to read the date of a nickel at 200 miles or watch a baseball game on the moon.

With such power, astronomers can now more easily track earth-threatening asteroids and comets, watch weather patterns on distant planets, and scrutinize galaxies for the birth of new solar systems.

About these ads

''This will bring a revolution across the world of astronomy - virtually every observatory in the world is heading this way,'' says Robert Brucato, assistant director of the Palomar Institute at the California Institute of Technology.

A bulkier prototype for the 100-inch system has been in use here on a 60-inch telescope for nearly two years. In San Jose, Calif., a 120-inch scope using adaptive optics is testing its system. There are also telescopes using the technology in Albuquerque, N.M., Hawaii, and Chile.

But for now, the Hooker scope boasts the sharpest view of the cosmos from the earth in history. Because of its capabilities, the Mt. Wilson staff claims it is poised to take the lead in the search for newly developing solar systems in the cosmic debris surrounding young stars.

''Hubble ended the Copernican revolution by displacing the sun from the center of the universe to a universe with no center,'' Baliunas says. ''We will accept and continue the legacy of Hubble by attempting to find out if we are alone.''

Explained by Mr. Shelton, who designed and fitted the telescope here with new technology, the key is to bounce incoming light off an auxiliary ''magic mirror'' - a nine-inch circular mirror able to change its shape thousands of times a second to cancel the effects of atmospheric turbulence.

A ''wave-front sensor'' divides an incoming beam of jumbled light into 240 parts and measures the rapid shifts in direction of each part. Eight computer processors work in tandem to direct ''actuators'' (pistons) behind the super-thin mirror to flex its surface. ''The machine bends the mirror out of shape so when the crooked light hits it, it comes off straight.'' Shelton says.

Adaptive optics was developed at a cost of more than $500 million, by one estimate, over several decades. An idea conceived of in the 1950s, adaptive optics was put on hold because fast and complex enough technology did not exist then.

The Department of Defense, which was looking to stabilize satellite-to-submarine communications and fine-tune lasers to disable incoming attack missiles, invested in developing the technology. It was later developed for the Strategic Defense Initiative.

Now, with the added advantages of miniaturized components and high-speed computers, the idea is both a reality and, comparatively, a bargain.

The new technology is expected to revive Mt. Wilson as a leading observatory. Once highly regarded as the site where astronomer Edwin Hubble developed his Big Bang theory of the universe's origin, the observatory's preeminence began waning as leading astronomers moved to bigger telescopes away from the polluting light of Los Angeles.

In addition to the work of Mt. Wilson's staff, the observatory expects to attract astronomers studying such topics as weather on Jupiter, Saturn, and Neptune. Until now, such investigation had to rely on expensive fly-bys of satellites that gave only instantaneous glimpses, ignoring long-term changes.

OBSERVERS say the importance of the new, powerful scope is that it multiplies the tools available to astronomers. ''There are ground-based, space-based, and radio-based telescopes, each of which has specific strengths a weaknesses,'' Brucato says.

''By newly expanding the capability of each of these old scopes, we free up the use of others to do what they are best at. In the long run, it multiplies the capabilities of everyone.

''When I first saw what this would do, I became very emotional,'' says Baliunas, an astronomer since 1974. ''This completely revolutionizes my job.''

Follow Stories Like This
Get the Monitor stories you care about delivered to your inbox.