NASA astronomers searching for asteroids headed toward Earth are expanding their sky-watching repertoire by adding high-tech, computerized electronic upgrades to the classic 1.2-meter- diameter (48-inch) Oschin telescope atop Palomar Mountain near San Diego, California.

Right now, NASA's Near Earth Asteroid Tracking (NEAT) system uses a fully automated charge-coupled device (CCD) camera mounted on a 1-meter-diameter (39-inch) telescope atop Mt. Haleakela on Maui, HI. The U.S. Air Force operates the telescope.

NEAT scientists will computerize the pointing system of the 1.2-meter (48-inch) Oschin telescope, which currently uses a human operator exclusively, and replace photographic plates with a modern electronic camera. The refurbished telescope will enable them to peer deeper into the sky than they can from Haleakela - they'll see 20 percent farther, and their field of view will be 10 times wider.

"Imagine watching the Super Bowl on your 25-inch TV and then switching to an 80-inch giant screen TV," said Dr. Steven Pravdo, NEAT project manager and co-investigator. "But in this case, it's even better than the TV analogy because, with the wider field, we'll see many more asteroids in each picture - those that would be on the 'sidelines' of other telescopes."

The NEAT-Oschin alliance got a test run on June 9 and 10, when Pravdo and two other JPL astronomers, Dr. David Rabinowitz and Jeffrey Schroeder, took the NEAT camera to the Oschin telescope. They obtained the first-ever electronic images from that venerable sky eye.

"This experiment proved that the Oschin telescope will be a powerful tool in our hunt for near-Earth objects," Pravdo said. "We'll spruce up this gentle giant and put it to excellent use helping us find asteroids,"

"For ten years, I've dreamed and mapped out plans for adding electronic detectors to this telescope," said Eleanor Helin, principal investigator for NEAT, which has been operating since December 1995. "We've been able to study only a fraction of the sky so far, and we've been looking for ways to cover the entire sky."

NASA's goal is to find all asteroids larger than 1 kilometer (0.6 mile) across within 10 years. "This will achieve one-third of that goal, with the remaining two-thirds filled by the Haleakela camera and other viewing sites," Helin explained. "The Oschin telescope at Palomar may become the premier finder of near-Earth objects in the world."

It's estimated there are 1,000 to 2,000 asteroids larger than 1 kilometer (0.6 mile) that approach within 48 million kilometers (30 million miles) of Earth. Less than 20 percent have been detected so far. Although the vast majority are harmless and will never pose a threat to Earth, scientists want to keep track of the tiny percentage whose orbits could eventually put them on a collision course with Earth.

The Oschin telescope, operated by the California Institute of Technology, Pasadena, CA, has served as a world-class telescope since it was built in 1949. Helin used the telescope to discover near-Earth asteroids and comets from the late 1970s to the early 1990s. The instrument is currently completing the second of two sky surveys that serve as a resource to astronomers worldwide. The Oschin telescope has done yeoman's duty for astronomers through the years, but it has been surpassed in many ways by newer, more advanced telescopes. Nonetheless, it remains the telescope with the largest field of view.

NASA will fund the Oschin upgrade, estimated to cost $300,000 to $500,000, and Caltech will provide the use of the facility and the infrastructure. Within about two years, astrophysicists from Yale University in New Haven, CT, may provide further high-tech upgrades to maximize the potential of the Palomar telescope.