Hawaii Or Spain? Telescope Experts Say It May Not Matter

When starlight from billions of years ago zips across the universe and finally comes into focus on Earth, astronomers want their telescopes to be in the best locations possible to see what’s out there.

Despite years of legal battles and months of protests by Native Hawaiian opponents, the international coalition that wants to build the world’s largest telescope in Hawaii insists that the islands’ highest peak — Mauna Kea — is the best place for their $1.4 billion instruments.

But just barely.

Thirty Meter Telescope officials acknowledge that their backup site atop a peak on the Spanish Canary island of La Palma is a comparable observatory location and that it wouldn’t cost more money or take extra time to build it there.

There’s also no significant opposition to putting the telescope on La Palma like there is in Hawaii, where some Native Hawaiians consider the mountain sacred and have blocked trucks from hauling construction equipment to Mauna Kea’s summit for more than a month.

But Hawaii has advantages that scientists say make it slightly better: higher altitude, cooler temperatures, and rare star-gazing moments that will allow the cutting-edge telescope to reach its full potential.

“Every once in a while at Mauna Kea, you get one of those magic nights,” said the University of California, Santa Cruz astronomy and astrophysics professor Michael Bolte, a Thirty Meter Telescope board member. “When the air is super stable above the site, you get images that you simply couldn’t get anyplace else.”

Bolte, who has used existing Mauna Kea telescopes, said those “magic” Hawaii nights could hold discoveries that might be missed in La Palma.

“Let’s suppose one of your big science cases is to look for life on planets that are orbiting other stars,” he said. “The star is so much brighter than the planet you’re trying to observe, it’s really hard to do.”