NASA's proposed upgrade of Keck has provoked opposition from native Hawaiian groups. Credit: NASA

A Hawaiian state agency is suing NASA over plans to upgrade the twin Keck telescopes on the mountain of Mauna Kea — the premier site for astronomical observation in the Northern Hemisphere.

The lawsuit, which was filed last week by the state's Office of Hawaiian Affairs, demands that the space agency completes a full Environmental Impact Statement (EIS) before carrying out its plan to build four to six small 'outrigger' telescopes that would improve Keck's ability to reveal planetary systems around distant stars. The case is seen as a significant escalation in a long- running battle between astronomers and native cultural groups in Hawaii.

NASA had hoped to be granted a state permit this month to begin construction later this year, and aimed to begin operating the outriggers in 2003. But completing an EIS would probably delay the project by a year or more, adding millions to its $50-million price tag.

The outriggers would operate as an interferometer with the two existing 10-metre Keck telescopes. This effectively produces the resolution of a much larger instrument. NASA wants to upgrade the facility primarily to study planets outside our Solar System, and says that four of its six science objectives cannot be accomplished without the outriggers.

The agency had hoped that a less formal “environmental assessment” of the outriggers' impact on the mountain would satisfy native Hawaiian groups, who have objected to the building of telescopes on a site that they hold sacred (see Nature 410, 1015; 2001). In February, NASA proposed having cultural and archaeological monitors present during construction, and offered $2 million in funding for cultural preservation and education projects in Hawaii. It also outlined a mitigation plan for the Wekiu bug, a threatened insect species that lives on Mauna Kea.

But the controversy “goes beyond the physical details to the spiritual aspects”, says Bill Stormont, director of the Office of Mauna Kea Management, which was set up by the University of Hawaii to manage the science reserve on the mountain. And many astronomers fear that the NASA case is simply a symptom of a worsening relationship between themselves and native Hawaiian groups, which may ultimately threaten Mauna Kea's future as an observation site.

Although NASA's outriggers are the only significant construction planned on the mountain for the next several years, the University of California is eyeing the site for its California Extremely Large Telescope project. Mauna Kea is also considered a logical site for a possible Next Generation Large Telescope project.

But such plans are facing an increasing number of potential roadblocks. A bill introduced in the Hawaiian legislature in March, for example, called for astronomers to begin paying rent to use mountains. Although the proposal died during committee deliberations, another bill, which calls for a moratorium on telescope construction on Mauna Kea until environmental assessments have been completed, has already been passed by the state senate.