Mauna Kea Telescope Scientists Summarize Lessons Learned After Dismantling

Scientists are weighing the implications of this summer’s move to remove the Caltech telescope from Mauna Kea’s summit after decades of mounting tensions with native Hawaiians.

The closure of the Caltech submillimeter observatory in July followed the closure of the University of Hawaii observatory a month earlier and came at a time of cultural revival among native Hawaiians.

“Nothing lasts forever,” said Gregory Chun, executive director of the Maunakea Care Center at the University of Hawaii and a Native Hawaiian.

“It was important that those two facilities were closed, not just because they were no longer productive, but because it’s a recognition of the privilege of being up there. You were bye-bye — you were done. So now you can go home.”

Noted for its altitude, dark skies, and low humidity, Mauna Kea still hosts 11 other telescopes. These facilities have brought Hawaii international recognition in astronomy and helped boost the local economy.

Now the Caltech telescope is moving to Chile under a new name (the Leighton Chajnantor Telescope), with new instruments and a chance to once again be at the forefront of cutting-edge astronomy.

Sunil Golwala, director of the observatory and a professor of physics at Caltech, said the team learned lessons from its time on Mauna Kea and that the Chilean site is far from population centers and not considered sacred. They will also build near other observatories to reduce their environmental footprint.

In the face of protests against the observatory, finding the right balance between astronomy and protecting Mauna Kea’s sacred site remains a challenge.

Despite the criticism, the telescopes actually benefit the state’s economy and support science and engineering in the islands, as many young Hawaiians leave to pursue education in these fields.

“There’s no consensus in the community — and certainly not in the Hawaiian community — about (the 3-Meter Telescope) or astronomy,” Chun said. “So balance is not going to be something that’s easy to find, but I think if the government can create a vision where people see themselves in it, we’ll have a better chance.”

During his time as the center’s director, Chun came to the conclusion that empathy is the path to reconciliation and authority is the opportunity to find it.

“We’ve definitely learned a lot of lessons and have a lot of scars that we’ve accumulated over the years,” Chun said.

“But I think it’s no coincidence that one of the most sacred lands here in Hawaii to Native Hawaiians is also the most important place, certainly in the Northern Hemisphere, if not the world, to practice astronomy.”

Native Hawaiians have long viewed the peak as a spiritual connection to heaven.

In 2019, protests erupted at the base of the mountain when Caletch and the University of California proposed building another observatory, called the Thirty Meter Telescope. The outcry prompted the state to transfer oversight duties from the University of Hawaii — which had leased the land to Caltech — to the new Maunakea Stewardship Oversight Authority, which is made up of local, environmental and scientific stakeholders.

The closing of the Caltech observatory marks the end of a controversial era as residents and new authorities debate the future of the mountain.

“I have incredible respect for the people of the University of Hawaii who are able to control their own actions,” said John De Fries, executive director of the new body. “If this body can begin to implement a new model of leadership, that is something to be thankful for, but the task is still ahead of us.”

In response to public criticism, the University of Hawaii created the Center for Maunakea Stewardship in 2020 to oversee operations on the mountain. It worked closely with Caltech to decommission the observatory.

Cultural observers were present throughout the process to ensure that the deconstruction was conducted in a respectful manner. Although the new body did not participate in the dismantling process, Caltech invited its members to participate in the cultural ceremonies at its conclusion.

A senior official also inspected the site to give final approval for the work to be completed and found that “the site has been restored to as close to its original condition as can be expected,” De Fries said.

With nearly three decades of observing, the Caltech Submillimeter Observatory has played a key role in several groundbreaking scientific discoveries in astrophysics.

The observatory was originally designed to detect some of the least-studied wavelengths of light, from one-third of a millimetre to 1 millimetre – much longer than the wavelengths of visible light.

This telescope, along with another telescope on Mauna Kea, the James Clerk Maxwell Telescope, discovered that Earth is bathed in light from excited particles living quietly in interstellar space.

By the end of the century, the upgraded Caltech Submillimeter Observatory had begun mapping the sky, a “quantum leap in capabilities,” Golwala said.

This has allowed scientists to map everything from the dust in the interstellar medium to the largest-scale structures in the universe, galaxy clusters.