HILO » The University of Hawaii has started writing an environmental impact statement for the 30-Meter Telescope proposed near the summit of Mauna Kea.

The TMT, as it is called, would have a main mirror 30 meters or 98 feet across. That would be far larger than the biggest telescopes ever built, the two 10-meter Keck telescopes now on Mauna Kea.

Like the Kecks, the TMT would be composed of multiple mirror segments computer-controlled to operate as a single mirror.

The TMT would be built by the University of California, California Institute of Technology, and an association of Canadian universities.

The university has scheduled a series of meetings during which officials will ask the public what should be in the environmental study.

The Big Island meetings will be Oct. 6 at Kohala High School cafeteria, Oct. 8 at Kahilu Town Hall (Waimea), Oct. 9 at Kealakehe Elementary cafeteria (Kona), Oct. 13 at Kau High School cafeteria, Oct. 14 at Keaukaha Elementary cafeteria (Hilo), and Oct. 15 at Pahoa High School cafeteria.

A Honolulu meeting will also be held Oct. 16 at the Blaisdell Center Pikake Room.

All meetings start at 5 p.m. except the ones at Kealakehe and Keaukaha, which start at 6 p.m.

If built on Mauna Kea, the TMT would be placed on the “;northern plateau”; of the mountain, about 500 feet below the summit.

If built in Chile, it would stand on Cerro Armazones, a mountain in the Atacama Desert in the north.

An environmental impact statement already written for the Chilean site says there is almost no vegetation there. The area is so dry that there is no evidence that native people ever used the area.

If built on Mauna Kea, the TMT is estimated to cost about $1 billion. If built in Chile, the cost is put at $750 million.

More information is available at http://www.tmt.org. The site gives no comparison of the scientific merits of Mauna Kea versus Chile.

Proponents hope to start construction in 2010 and have the telescope operational in 2018.