A police officer monitors the situation as protestors block a road at the base of Mauna Kea.Credit: Caleb Jones/AP/Shutterstock

Hundreds of protestors have blocked construction of the Thirty Meter Telescope (TMT) on Mauna Kea in Hawaii. Thirteen astronomical observatories that call the mountain home have evacuated workers and curtailed their operations.

Work on the TMT was set to resume on 15 July after a four-year delay caused by legal challenges and protests. Hawaii’s state supreme court ruled in October that the TMT’s construction permit was valid.

But last weekend, opponents of the telescope began gathering at a site at the base of the access road that leads up Mauna Kea. They sang, held signs and spoke out against the TMT, which they believe will further despoil a sacred mountain.

“I honestly don’t know how this is going to end,” says Doug Simons, an astronomer and executive director of the Canada-France-Hawaii Telescope, one of the observatories on the mountain.

Lost nights

The observatories on Mauna Kea’s summit — which include some of the world’s largest, such as the twin 10-metre Keck telescopes and the 8.2-metre Subaru Telescope — stopped collecting data and ordered employees and researchers to evacuate on 16 July.

Affected projects include Andrea Ghez’s ongoing studies of the centre of the Milky Way. Ghez, an astronomer at the University of California, Los Angeles, had planned to use one of the Keck telescopes on 16 July to collect data on the motion of stars around the supermassive black hole at the centre of the Galaxy. Scientists use such information to test predictions of general relativity.

But Ghez isn’t bothered by Keck’s temporary closure. “If I lose a night in order that everyone can figure out how to move forward in the long run, that’s far more important than one night of observing,” she says.

Mihoko Konishi, an astronomer at Oita University in Japan, had planned to use the Subaru Telescope between 16 and 18 July to study disks of planet-forming dust and gas around other stars. “I know Mauna Kea is a sanctuary for Hawaiians, so I hope [for] a peaceful settlement for both sides as quickly as possible,” Konishi says.

Some of the telescopes atop Mauna Kea can be operated remotely, without staff on-site. But facility managers opted not to do that in case something went wrong that observatory staff couldn’t handle from afar. “We anticipate returning to normal operations as soon as the situation allows,” said Jessica Dempsey, deputy director of the James Clerk Maxwell Telescope, in a 16 July statement.

A sacred place

Hawaii governor David Ige signed an emergency proclamation on 17 July that allowed law enforcement to close more sections of road around the base of Mauna Kea.

By then, TMT opponents had established a pu’uhonua — ‘place of refuge’ in Hawaiian — and started flying the Hawaiian flag upside-down as a sign of distress. Seven protestors had chained themselves to a cattle grate in the road leading up to the summit on 15 July, although they later detached themselves.

“Our objective is to stop TMT,” said Kaho’okahi Kanuha, a leader of the protestors, during a 16 July press conference. “We’re against the destruction of our mauna,” or mountain.

Ige has said that opponents who block access to the TMT construction site are breaking the law. Police took 33 Native Hawaiian elders into custody on 17 July before citing and releasing them almost immediately.

Astronomy graduate students published an open letter on 17 July asking, among other things, for the state to withdraw law enforcement officers from Mauna Kea. As of 18 July, hundreds of astronomers have signed it.

“We have been trying to balance and maintain access to Mauna Kea in a way that would be respectful,” Ige said in a press conference on 17 July. He added that Native Hawaiian practitioners have long revered the mountain, and visit it for sacred ceremonies.

Other demonstrations related to the TMT project — mostly opposing it — have broken out across the Hawaiian islands in the past few days, including in the state’s capital of Honolulu.