Sunday, April 25, 2004

University of Hawaii astronomers Kenneth Chambers, left, Nicholas Kaiser and John Tonry are among those who will be looking for "killer asteroids." These types of asteroids are what are thought to have killed off the dinosaurs. They are developing a telescope array called the Panoramic Survey Telescope and Rapid Response System to detect such asteroids, which will also track other objects in space, such as stars, galaxies, planets, comets, supernova and gamma-ray bursters.

Coming soon:
Asteroid hunters

UH astronomers are working
on a telescope array
to detect killer asteroids

Asteroid Watch

Panoramic Survey Telescope and Rapid Response System, called Pan-STARRS:

Concept: A powerful array of four small telescopes with innovative technology will survey large regions of sky and detect faint asteroids that could threaten Earth.
Developer: University of Hawaii Institute for Astronomy; principal investigator, astronomer Nicholas Kaiser.
Total estimated cost: Roughly $50 million.
Location: Haleakala, Maui, for the first prototype telescope; either Haleakala or Mauna Kea for the full system.
Time frame: First telescope expected to be operating by Jan. 1, 2006, with others to go up for full operation by the end of 2007.

If one of the thousands of asteroids hurtling through space crashes into Earth, the damage could equal 700 Hiroshima-size bombs blasted at once.

The potential danger of a collision with a 198-foot asteroid was pointed out recently to a U.S. Senate science committee by astronaut Ed Lu, who calls Honolulu one of his hometowns. He said there is a 10 percent chance of this happening.

The first warning of a small killer asteroid could come from a special array of four small telescopes planned in Hawaii.

The first telescope in the Panoramic Survey Telescope and Rapid Response System, called Pan-STARRS, is scheduled to be operating in two years on Haleakala, Maui, to test the system.

"The project serves as a guardian," said Kenneth Chambers, of the University of Hawaii Institute for Astronomy. Chambers is principal scientist for the first prototype telescope.

"We want to find them as far in the future as we can because it's much easier to do something about them," he said.

The full telescope array will either be at Haleakala or Mauna Kea, on the Big Island, depending on environmental and site studies under way.

When it is completed, the scientists expect to detect about 100,000 asteroids a month, said UH astronomer Nicholas Kaiser, principal investigator for the estimated $50 million Pan-STARRS project.

"Most of those will be harmless," he said. "We're looking for the odd, bad one."

Lu and astronaut Rusty Schweickart urged the Senate committee to use unmanned spacecraft to test methods of bumping an asteroid from an impact course with Earth. Lu said such capability could save the planet if space surveys warn of an approaching asteroid years in advance.

That is the prime mission of Pan-STARRS, Chambers said, describing it as a "time machine." The goal is to find 99 percent of asteroids that could significantly damage Earth, determine their orbits and predict what they will do in 20 to 50 years, he said.

The system will enable astronomers to detect objects as small as 330 yards in diameter and 100 times fainter than those observed by other telescopes.

Instead of looking through telescopes to understand what happened in the past, Chambers said, astronomers will be looking at what will happen in the future.

Repeatedly sweeping big patches of sky, he said, "we can find the ones that will be a threat in the future and those that will zoom by but are not going to do any harm, and only get worked up by those that are a threat."

NASA's LINEAR survey project in New Mexico is concerned about asteroids about six-tenths of a mile in diameter and larger, which have the greatest potential for a catastrophic crash into Earth. It is believed one wiped out the dinosaurs 65 million years ago.

The smaller ones that can be scrutinized by Pan-STARRS "are less hazardous and less massive, but there are a hell of a lot more of them," Kaiser said.

"If they're under 300 meters," said Chambers, "they may wipe out a city or cause a tidal wave, but we will not have mass extinction of the species or global climate change, what the big ones can and have done in the past and will do in the future."

But Pan-STARRS is not just an asteroid hunter, Chambers said. It also will track other moving objects in space: stars, galaxies, planets, comets, supernova and gamma-ray bursters.

Covering the whole sky night after night "will provide a movie not only of our solar system, but of our galaxy and of our universe," Chambers said.

This will give astronomers predictive capability "even out to cosmological scales," he said. "We'll be able to measure the geometry of the universe and the fate of the universe, as well."

The Air Force has provided $20 million to build the first telescope, expected to be in operation by Jan. 1, 2006. Money is being requested for the other three, Kaiser said.

He said they hope to put one up every six months so the full array will be operational by the end of 2007.

NASA's Lunar Ranging Facility is being phased out on Haleakala, and Pan-STARRS will use the existing building with some modifications, Kaiser said.

He said Pan-STARRS will be the most powerful instrument by far for any astronomy that requires rapid imaging of large patches of the sky over and over again.

Instead of one large mirror, each of the four telescopes, each nearly 6 feet in diameter, will have very large, state-of-the-art electronic cameras with extremely fine resolution of 1 billion pixels. The full array will have 4 billion pixels.

The most powerful survey instrument now is 300 million pixels at the Canada-France-Hawaii Telescope on Mauna Kea, Kaiser said. A pixel is the smallest element of a digital image.

Its field of view is 1 square degree, he said, noting the moon's diameter is half a degree.

Pan-STARRS will cover 7 square degrees of sky at once -- 40 times the area of the full moon, Kaiser said.

"This is what we've got to do to catch asteroids, to scan thousands of degrees every night. ... They're a moving target," he said.

Chambers said Pan-STARRS is innovating camera, computer and telescope technology.

"The camera itself would be considered a supercomputer only a few years ago," he said.

UH astronomers acquiring patents for leading-edge technology are John Tonry, who invented the detector device, and Klaus-Werner Hodapp, who developed a method of obtaining more pristine data from the atmosphere.

Kaiser said about 100 people are working on Pan-STARRS, including UH scientists and students. The Lincoln Laboratory at the Massachusetts Institute of Technology is building the detectors.

Pan-STARRS is collaborating with the Maui High Performance Super Computer to process the unprecedented volume of data.

But Chambers said the project will build a specialized supercomputer. "When the fire hose is turned on, we will be hit with the biggest data stream in history," he said, with about 3,000 gigabytes of data nightly.

"We have to be able to push it through and reduce it at the end at the same rate it is coming in, so we're on the forefront of computer technology to do that," Chambers said.

He said a large number of small, cheap computers will be connected with innovative software to take the raw data from the sky and process it at once.

Kaiser said a spinoff application of the telescopes is to detect transient things like gamma-ray bursts, the brightest objects in the cosmos, and process the data within minutes to alert bigger telescopes to follow up on them.

"Ultimately," Chambers said, "the images that will come out of this will be so spectacular ... it boggles the mind.

"When we do an IMAX fly-through the universe, that will be pretty amazing."

Aside from pioneering astronomy, he said the Air Force is providing money through Pan-STARRS to relocate the TV broadcast towers on Haleakala because the transmissions would interfere with the telescope. The broadcast stations are collaborating with the project, and the antenna site will be restored, he said.

Pan-STARRS also will provide cultural training for everyone who works on the mountain, from construction crews to scientists, "so they know how to behave and respect the mountain," Chambers said.

"At the end of the project, the mountain will be in better shape than it is today, and the planet will be safe."

Cox News Service contributed to this report.


Recent impact scare
leads to new formal
reporting procedures

Some astronomers on Jan. 13 were close to alerting the government that an asteroid 1,650 feet wide would hit the Earth within two days.

Observations the next night showed the asteroid was not a threat, but the scare has led to a formal process of warning the president about potentially dangerous asteroids.

The trajectory impact of asteroid 2004 AS1 would have been imminent, within 24 hours, said Dave Tholen, a University of Hawaii planetary astronomer recognized internationally for his work on asteroids.

Computations based on the first four observations of AS1 by the Lincoln Near Earth Asteroid Research project in New Mexico had the asteroid hitting the Earth's northern hemisphere the next day about 4 p.m. Hawaii time, he said.

NASA's 10-year Spaceguard Survey Program, launched in 1998 to map objects coming within 120 million miles of the sun, "never conceived of discovering anything within 24-hour notice," Tholen said. "There were no procedures to deal with that."

Because of the Jan. 13 event, NASA is clarifying the process of notifying top officials of a possible asteroid impact.

Tholen said there was confusion over AS1 because the first of four observations on Jan. 13 computed by the planet center to help astronomers find it the second night turned out to be wrong.

A lot more noise than usual associated with the measurements caused the discrepancy, he said. "One position made all the difference in orbit confirmations."

The asteroid was nowhere close to where it was predicted when it was found the second night, he said.

It was bigger than expected, about 1,650 feet, and farther away than predicted, about 7 million miles, and posed no danger, he said.

The event didn't make the news until a month later when someone mentioned it in a talk at a conference, he noted.

Another asteroid discovered March 18 excited astronomers because of the rare chance for an up-close look at a small space rock.

Asteroid 2004 FH, about 100 feet in diameter, was reported to be the closest asteroid flyby of Earth ever recorded, passing 26,500 miles above the surface.

"It was supposed to be some sort of record for something coming very close," Tholen said, "but it also is a little bit of hype.

"Some people tend to forget in 1972, we actually had something graze the atmosphere and was visible over several states in the Rocky Mountain region."

It was 40 miles above Montana at its lowest point.

The newly discovered asteroids weren't the type to wipe out a species, Tholen said. But depending upon their composition, they were potentially threatening in that they could have hit the ground and caused a crater or exploded in the atmosphere, he said.

Former UH planetary astronomer David Morrison, now comet and asteroid impact hazard expert at NASA's Ames Research Center, said in a March 23 article on the Internet that asteroids the size of FH come close to Earth roughly once every two years and one hits the Earth every few decades.

"But for the first time, we are now able to detect some of these small visitors," he said.

"Perhaps this information will help us to develop a better sense of our cosmic environment, where space rocks go sailing past the Earth at high speed every day."


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