
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, August 20, 1993                   TAG: 9308200011
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-5   EDITION: METRO 
SOURCE: Associated Press
DATELINE: ALBUQUERQUE, N.M.                                LENGTH: Medium

NEW TELESCOPE TO PROVIDE VIEW OF UNIVERSE'S BOUNDS

The world's biggest astronomical instrument, a 5,000-mile-wide radio telescope, is being dedicated today, and scientists hope it will unravel mysteries from the edge of the universe to the Earth's surface.

The instrument, stretching from the Virgin Islands to Hawaii, is a series of 10 computer-steered antennas, each 240 tons, 82 feet wide and nearly 100 feet tall when pointed straight up.

"It's a very versatile instrument designed primarily for astronomy," said Joan Wrobel, a National Radio Astronomy Observatory staff astronomer.

The Very Long Baseline Array radio telescope also can be used for precise measurements of the movement of Earth's crust to study earthquakes. And it can be used for accurate measurements of variations of the Earth's rotation to improve time keeping, navigation and spacecraft tracking.

It can record high-resolution images of celestial bodies emitting electromagnetic radiation, in wavelengths ranging from about 1 meter to 7 millimeters, billions of light-years away. A light-year is the distance light travels in one year - about 5.9 trillion miles.

Construction of the VLBA began in 1985 and has cost $84 million.

The antennas are pointed at an object by computers via land lines from the observatory at New Mexico Tech in Socorro.

The first two dishes first produced a correlated signal in 1989. All 10 dishes went on line in May.

With all 10 operating, the VLBA has up to 1,000 times more resolution than any other radio telescope. Analogy: The human eye can see a car wheel a mile away; the VLBA can read a newspaper in Los Angeles from Washington, D.C.

The 10 VLBA sites gather and record signals from space. Tapes are mailed to Socorro - to keep costs down - and there computers produce images the eye would see if it could see radio wavelengths.

The VLBA has "the ability to make movies of objects that are extremely far away, like quasar cores. Something at the edge of the observable universe," said Craig Walker, Wrobel's husband and an astronomer at the observatory.

Other telescopes can take only snapshots of large distant objects, he said. "With the VLBA, we can see things on the order of a light-year in size at the edge of the universe."

by CNB