Officials proceed with groundbreaking ceremonies for the world's largest optical telescope amid protests from native Hawaiians who oppose it.

Under beautifully clear skies — just the kind that have made the summit of Hawaii's Mauna Kea a mecca for astronomical observatories — officials gathered on October 7th for the dedication and groundbreaking of the Thirty Meter Telescope.

The ceremony demonstrated the combustible mix of science, local traditions, and politics that have dogged the summit's development for decades and the TMT project in particular. The ceremony was interrupted for several hours as local opponents staged a peaceful protest, using their cars to block the road leading to the summit. Some held signs using TMT to spell out "Too Many Telescopes."

Mauna Kea, often translated as "White Mountain" because it's sometimes capped with snow, rises 13,796 feet (4,205 m) from the Pacific Ocean and is sacred to native Hawaiians. The dormant volcano is known locally as wao akua ("realm of the gods"), and its slopes are dotted with shrines, altars, and hidden burial grounds.

According to the master plan drawn up in 1983 (extended in 2000) between state environmental officials and the University of Hawaii, which manages the summit, no more than the 13 domes can be built on the summit. This limitation ultimately led to cancellation of plans to add four small "outrigger" telescopes to Keck Observatory's existing giant twin domes.

TMT: A Monster Telescope

Despite the protests, construction for the TMT has been approved and will move forward. When completed, perhaps as early as 2022, the telescope will leapfrog to the top ranking of the world's largest optical telescopes.

Exploiting technology pioneered for the twin Keck telescopes, the TMT will combine 492 individual hexagonal reflectors, each 1.4 meters across, honeycombed together to yield a primary mirror with an effective diameter of 30 m (98 feet). That giant primary will provide 144 times more collecting area and 10 times better spatial resolution than the Hubble Space Telescope.

"This is an exciting moment as we begin construction of TMT," noted Edward Stone in a prepared statement. A veteran Caltech space physicist, Stone serves as executive director of TMT International Observatory (though he's better known as project scientist for NASA's Voyager mission).

TMT is the first of what could be multiple mega-telescopes designed to vastly improve the ability of ground-based telescopes to peer into the faint, deep cosmos. The race is on to build TMT and two competing projects: the 27-meter Giant Magellan Telescope (GMT) and the European Extremely Large Telescope (EELT).

Such "megascopes" should open the door to major discoveries in all facets of astronomy. Finding the composition of distant exoplanets, mapping the large-scale structure of the universe, and probing the earliest galaxies are all on the long "to-do" list that astronomers are drawing up for the TMT. Plans call for three "early light" instruments: a wide-field, multiobject spectrograph (WFOS); a near-infrared imaging spectrometer (IRIS); and a multi-slit, near-infrared imaging spectrometer (IRMS). The telescope will utilize an adaptive-optics system to cancel out atmospheric turbulence and achieve diffraction-limited performance.

It's an enormous project, both physically (the summit site covers about 5 acres) and financially. With an estimated price tag of $1.4 billion, TMT is too costly for any one institution to undertake. Instead, it's a joint international venture involving the California Institute of Technology, Chinese Academy of Sciences, Japan's National Institutes of Natural Sciences and National Astronomical Observatory, and the University of California. India and Canada plan to join the partnership soon.

Read contributing editor Robert Zimmerman's article about the construction mega-telescopes in the March 2014 issue of Sky & Telescope.