HONOLULU — Astronomers have stopped peering through 13 telescopes on top of Hawaii’s tallest peak as protesters block the road to try to prevent construction of a giant observatory on the mountain that some Native Hawaiians consider sacred.

Dozens of researchers from around the globe won’t be able to gather data and study the sky atop Mauna Kea, one of the world’s best spots for astronomy with clear weather nearly year-round and minimal light pollution.

Observations won’t resume until staffers have consistent access to the summit, which is needed to ensure their safety, said Jessica Dempsey, deputy director of the East Asian Observatory, one of the existing telescopes.

”Our science time is precious, but in this case, our priority is just to make sure all of our staff is safe,” Dempsey said.

The announcement came as Native Hawaiian protesters blocked the base of the road for a second day Tuesday. They object to construction of the $1.4 billion Thirty Meter Telescope, which is expected to be one of the world’s most advanced when it’s built, out of concern it will further harm the mountain.

Hawaii authorities haven’t arrested any protesters but have indicated they would. Law enforcement was focused on preparing a path to construction, said Jason Redulla, chief of the state Division of Conservation and Resources Enforcement.

Protesters said they told authorities that they would allow telescope technicians to pass if they could drive one car to the summit each day for cultural and religious practices. No agreement was reached.

The East Asian Observatory was scheduled to study carbon monoxide clouds in star-forming regions inside the Milky Way on Tuesday night. Dempsey called the clouds “the DNA of how baby stars form” and said they help astronomers figure out how stars work.

Officials closed the road to the top of the mountain starting this week to allow construction to begin, attracting hundreds of protesters who formed their own roadblocks.

Gov. David Ige has said unarmed National Guard units would be used to transport personnel and supplies to the peak but would not be used as law enforcement during the protests.

Demonstrators said they wouldn’t allow National Guard members to pass.

Kaho’okahi Kanuha, one of the protest leaders, told reporters that efforts to stop the Thirty Meter Telescope were about protecting Hawaii’s indigenous people.

”This is about our right to exist,” he said. “We fight and resist and we stand, or we disappear forever.”

Other Native Hawaiians say they don’t believe the Thirty Meter Telescope will desecrate Mauna Kea. Most of the cultural practices on the mountain take place away from the summit, said Annette Reyes, a Native Hawaiian from the Big Island.

”It’s going to be out of sight, out of mind,” she said.

Reyes said others agree, but they’re reluctant to publicly support the telescope because of bullying from protesters, a group she calls a “vocal minority.” She says she’s been called a fake Hawaiian for supporting the project.

Reyes said Hawaii’s young people can’t afford to miss out on educational opportunities, citing telescope officials’ pledge to provide $1 million every year to boost science, technology, engineering and math education.

She challenged the characterization of the dispute as a clash between science and culture, saying science was an integral part of ancient Hawaiian lives.

”Everything they did was science, from growing fish and taro to wayfinding,” Reyes said.

The project has been delayed by years of legal battles and demonstrations. Last year, the Hawaii Supreme Court ruled that telescope officials had legally obtained a permit, clearing the way for construction to begin.

Telescope opponents last week filed another petition in court, saying the project must post a security bond equivalent to the construction contract cost before starting to build.

Doug Ing, an attorney for the Thirty Meter Telescope, said the latest lawsuit has no merit and is another delay tactic.

The company behind the project is made up of a group of universities in California and Canada, with partners from China, India and Japan.