Asteroid tracker due for isles

Hawaii astronomers say Mauna Kea is the preferred site for the new telescope facility

Mauna Kea would be the best place scientifically for a proposed telescope to track potentially dangerous near-Earth asteroids and comets, a Hawaii Institute for Astronomy official said.

If Mauna Kea is chosen over Haleakala, Maui, for the Panoramic Survey Telescope and Rapid Response System, known as Pan-STARRS, it would replace the University of Hawaii's 88-inch telescope, said Mike Maberry, IFA assistant director for external relations.

PUBLIC COMMENT INVITED Public meetings to obtain comment for a draft environmental impact statement for the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS, will be held Jan. 23-31 on the Big Island, Maui and Oahu. Doors will open at 5:30 p.m. and meetings will start at 6 p.m. as follows: BIG ISLAND » Jan. 23 at Kealakehe Intermediate School Cafeteria » Jan. 24 at the Waimea Civic Center » Jan. 25 at Hilo Campus Center MAUI » Jan. 30 at Cameron Center OAHU » Jan. 31 at the UH-Manoa's Center for Hawaiian Studies, Kamakakuokalani Building After presentations on the proposed telescope, people will be allowed to ask questions and make comments, which will be documented as part of the environmental process.

The 88-inch is "extremely productive, an excellent tool for students and faculty," Maberry said. But it is more than 35 years old and expensive to maintain, he said.

Hearings are scheduled for this month on the Big Island, Maui and Oahu to get public comment for development of a draft environmental impact statement for Pan-STARRS.

A prototype of the telescope is being developed on Haleakala, where two sites offer a possible alternative to Mauna Kea for a permanent system. One is undeveloped, Maberry said. The other was used previously for a radio telescope but is now a flat area, he said.

Pan-STARRS' purpose is to detect and track asteroids and comets on a threatening path toward Earth. It will also survey other moving objects in space.

Funding is provided through an agreement administered by the U.S. Air Force Research Laboratory. The UH will support maintenance and operation of Pan-STARRS and be responsible for processing what is expected to be a deluge of data and images.

The $50 million system will have four telescopes, each with a digital camera with about 1.4 billion pixels. Working together, they will survey the visible sky once a week to help NASA reach its goal to categorize near-Earth objects larger than about 460 feet in diameter.

A digital camera with more than 300 megapixels will be installed on the PS1 telescope next month, Maberry said. "It will be the largest digital camera in the world, even though it is only one-quarter of the final camera."

The prototype is being developed to test the technology for the full Pan-STARRS system, and it is expected to be fully operational by the end of this year, Maberry said. IFA astronomer Kenneth Chambers is project scientist for the PS1 survey.

Maberry, based on Maui, said scientists are waiting for some optical elements to arrive, the largest astronomical filters ever made and a secondary mirror.

"We have a primary mirror but not secondary," he said, adding that a temporary secondary mirror is allowing astronomers to do some important alignments and tests.

Geological, biological, mechanical and scientific surveys have been done of the proposed Pan-STARRS sites on Mauna Kea and Haleakala, Maberry said. And Mauna Kea is considered the prime site for the unique telescope for several reasons, he said.

"Prevailing tradewinds tend to bring clouds up out of the crater over the Haleakala Observatory site, so we experience more clear nights on Mauna Kea and nights where the 'seeing' disturbance is less."

The four largest cameras in the world also will be very sensitive and susceptible to light pollution, and the Big Island has a lighting ordinance that controls light pollution, he said.

"Maui, even though we've been trying for six years, doesn't have a good lighting ordinance, and we do have a lot of light pollution."

Another advantage of Mauna Kea is the distance of the summit from populated areas, which enhances the site for nighttime astronomy, Maberry said.

The UH's Mees Solar Observatory was the first on Haleakala, deemed the best place in the world for solar observations, Maberry said.

Haleakala might rank second to Mauna Kea for the four Pan-STARRS telescopes, but the 10,023-foot Maui summit is the chosen site for the $180 million Advanced Technology Solar Telescope.

The ATST is about a year ahead of Pan-STARRS in the development process, Maberry said. A draft environmental impact statement was published last fall.