If you are going to spend more than a billion dollars building one of the world's biggest telescopes, you'll want to put it in a place with the best possible view of the stars. But in the case of the Thirty Meter Telescope, an instrument that promises unprecedented images of everything from the most distant galaxies to nearby exoplanets, builders may have to settle for second best. Next week, the fierce legal and cultural battle that has engulfed efforts to build the TMT on Mauna Kea, a 4207-meter-high peak in Hawaii, will reignite as state officials open a pivotal hearing on whether to allow construction. The peak is rated as the best observing site in the Northern Hemisphere, but for Native Hawaiians it is sacred land, and many residents oppose the project.