As a bitter, multi-year battle over the legality of the Thirty Meter Telescope (TMT) rages on, an alternate path forward has begun to emerge. The world's largest telescope may not wind up on the frosty peak of Mauna Kea, Hawaii, but instead it might be placed in Spain's Canary Islands. It'd be a loss for astronomy, but a major win for Hawaiian cultural practitioners who don't want their sacred mountain marred by gigantic machines. Artist's rendering of the Thirty Meter Telescope. Image: TMT.org
A $US1.4 billion ($1.8 billion) observatory designed to peer into the furthest corners of space and back to the beginning of time, the TMT is the largest in a series of extremely large ground-based telescopes (ELTs) which, along with the James Webb Space Telescope, are intended to lead astronomy in the 2020s. The telescope, which is intended to do optical and infrared astronomy and address questions ranging from the origin of the universe to the habitability of exoplanets, is the only ELT slated to be built in the northern hemisphere. That makes it an indispensable tool for acquiring high-resolution images of certain portions of the sky.
But the knowledge to be gained from the TMT comes at a steep price. Its intended construction site, atop the dormant volcano of Mauna Kea, is considered sacred ground by native Hawaiian people. To these men and women, a structure this large would be a desecration. And after watching 13 other observatories get built on Mauna Kea since the 1970s, Hawaiians who want to preserve traditional cultural practices and burial sites are finally making sure their voices are heard.
Protests and legal disputes over the telescope have been ongoing for years. Things came to a head last December, when Hawaii's Supreme Court nullified the TMT's construction permits on the basis of a due process lawsuit brought by the telescope's opponents. The TMT's board of governors have spent the last 10 months trying to figure out where the hell to go from here.
Today, that board reached a decision that ensures the scope will survives in some form, but also acknowledges the challenges that lie ahead. If the telescope cannot be built atop Mauna Kea -- still a big if, with TMT officials in the process of seeking seeking a new construction permit -- the project could be moved to the island of La Palma.
Located in Spain's Canary Islands, La Palma is already home to the Roque de los Muchachos observatory, one of the world's leading optical observatories. After Mauna Kea, it's considered the second best location for optical and infrared astronomy in the northern hemisphere. "We could really move forward quickly should things not work out [at Mauna Kea]," Caltech astrophysicists and TMT board member Fiona Harrison told Nature News.
But La Palma also has its drawbacks: Astronomers would be sacrificing some 2000m of elevation, meaning it'd be subject to more interference from Earth's atmosphere. This could reduce the scope's resolution, particularly in mid-infrared wavelengths needed to observe galactic centres.
One the other hand, moving the TMT would honour the wishes of native Hawaiians who feel their opposition to astronomy on the mountain has been marginalised for decades. And that could go a long way toward preventing a clash between gods and astronomy from becoming all-out war.