On January 28 the National Astronomical Observatory of Japan exhibited the "first light" snapshots from Subaru, a new, world-class optical and infrared telescope built atop Mauna Kea, the 4,205-meter (13,796-foot) dormant volcano on Hawaii's Big Island. Subaru joins about a dozen telescopes with mirrors that measure at least eight meters in diameter that are achieving first light through the turn of the century. These giant light-collecting machines include another Mauna Kea resident, the Gemini North Observatory, backed by the U.S. and six other nations, which is nearing its own first-light images.
Subaru, the Japanese word for the Pleiades star cluster, boasts the planet's largest single-piece mirror, an 8.3-meter-diameter wonder (others are larger but consist of separate pieces). Shaped like a contact lens, the 20-centimeter-thick meniscus mirror maintains its shape via 261 computer-controlled supports that continually adjust the surface to prevent flexing or sagging. The instrument, which marks Japan's entrance into big-time infrared and optical astronomy, is the most expensive ground-based telescope ever built. The telescope, eight years in construction, cost some $350 million--and took the lives of three workers, who died in a fire in the dome in 1996.