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Construction of Hawaii's controversial Thirty Meter Telescope is cleared to proceed

A rendering of the Thirty Meter Telescope.
A rendering of the Thirty Meter Telescope.
(Thirty Meter Telescope Corporation)
  1. On Tuesday, Hawaii Governor David Ige announced that construction could proceed on the Thirty Meter Telescope (TMT), a controversial telescope planned for Mauna Kea.
  2. In exchange for the approval, Ige said, at least one-quarter of the existing 13 telescopes on Mauna Kea must be decommissioned.
  3. Construction of the telescope has been halted since April due to protests by Native Hawaiians, who object to its placement on a sacred site.
  4. If completed, the TMT would be the world's second-largest telescope, and would allow astronomers to learn more about the early stages of the universe.
  5. It's still uncertain when construction might actually restart.

Why astronomers want to build a giant telescope

thirty meter telescope

(Thirty Meter Telescope Corporation)

In 2000, a group of US universities (including Caltech and the University of California) embarked on a plan to build what would be the world's largest telescope — one with a 30-meter-wide composite mirror — on Mauna Kea.

There's a simple reason astronomers want a bigger telescope: the bigger the mirror, the more light a telescope can collect. And the more light collected, the farther astronomers can see. Giant telescopes have allowed people to observe galaxies so far away that the light took billions of years to travel between them and Earth — in effect, revealing distant regions of space as they were billions of years ago.

The TMT's even-more-massive mirror would let astronomers see farther than any optical telescope currently on Earth: about 13 billion light years away.

Because the universe is believed to be 13.8 billion years old, this means the TMT would allow astronomers to look all the way back to a few hundred million years after the Big Bang — to the so-called "dark ages," when light first began to travel freely through space. Observations of this era could help us better understand the exotic processes that allowed this to occur and the universe to form.

A giant telescope like the TMT would also allow astronomers to look at objects closer to us in greater detail. Along with a similarly huge telescope being built in Chile (which will look at a different part of the sky), the TMT could let scientists analyze the atmospheres of exoplanets, and perhaps even find signs of life.

For all these reasons, the California universities joined with a number of other scientific organizations to build the TMT, at a total cost of $1.4 billion. The groups considered sites in Chile and Mexico, as well as Mauna Kea, and eventually decided on the latter. In 2011, they got permission to build.

Why some Hawaiians have protested the TMT

Astronomers had previously built 13 other telescopes on Mauna Kea dating back to 1968, and protestors consider them a desecration. "For Kanaka Maoli [Native Hawaiians], Mauna Kea calls us to be faithful to our ancestral connections to her, to defend our beliefs, values and practices and to demonstrate aloha ʻāina," Jon Osorio, a professor of Hawaiian Studies at the University of Hawaii, recently told Wired.

Traditionally for Hawaiians, the mountain is the home of several deities, and a place only to be visited for special ceremonies. Locals have prayed, built shrines, and in some cases buried ancestors on Mauna Kea for generations. The fact that the TMT will be much taller (18 stories) and take up much more space on the mountain (1.44 acres) than any previous telescope makes it an especially big problem.

The colonial history of the Hawaiian islands is also relevant here. In 1893, a small group of US-supported businessmen overthrew Hawaii's queen, leading to the breakup of the Kingdom of Hawaii and the eventual annexation of the islands by the US. Americans have since flooded the islands, and today Native Hawaiians have significantly higher rates of poverty than whites. Against this backdrop, the TMT — and astronomy's takeover of Mauna Kea — looks like the latest advance of Western colonialism in Hawaii.

Finally, some environmentalists are concerned about the ecological impact of yet another telescope. Though an environmental impact assessment was conducted, groups like Mauna Kea Hui say it wasn't sufficient, and are worried that waste produced by the increased amount of activity on Mauna Kea facility could damage the island's aquifer.

How protestors halted construction of the telescope

A L O H A ʻĀ I N A DLNR arrests made at the Northern Plateau #TMTshutdown

A photo posted by Protect Mauna a Wākea (@protectmaunakea) on

Many protesters had opposed earlier telescopes, and they began protesting the TMT during the public review process: an activist group called Mauna Kea Ohana, for instance, sued in 2011 but was unable to stop construction.

However, their protests during the October 2014 groundbreaking were the first to occur directly on the mountain, and they brought the ceremony to a stop. Unlike before, news of their protests spread on social media and garnered support far beyond the islands.

Tensions peaked during March and April, as protestors camped on the mountain and blocked the access road, with police arresting some of them. On April 7, Governor Ige called for a one-week halt to construction.

What's going to happen next

mauna kea

There are 13 telescopes on Mauna Kea so far. (Subaru Telescope)

After meeting with parties on both sides, on Tuesday Ige announced that construction could proceed — but that there'd be new rules for managing development on Mauna Kea in the future. "We have in many ways failed the mountain," he said. "We have not done right by a very special place."

For the TMT construction to proceed, Ige said, at least one-quarter of the existing telescopes on the mountain have to be decommissioned by the time TMT is operational in the mid-2020s. (Presumably that means at least four telescopes.) One particular telescope — the Caltech Submillimeter Observatory — was already planned to be dismantled, but it's unclear which other ones might be taken down.

Additionally, the University of Hawaii — which owns and administers the land on Mauna Kea — must commit to not building telescopes on any new areas of the mountain. When its lease ends in 2033, the university must turn over all land not needed for astronomy to the Hawaii Department of Land and Natural Resources. Finally, Ige called for the creation of a Mauna Kea Cultural Council, which will consider cultural issues in managing use of the mountain more carefully.

At the moment, it's uncertain whether protestors will be satisfied by these new terms, and there's no set date for construction on the TMT to restart.

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