Hawaiian Supreme Court gives go-ahead to giant telescope

Two large white domes on a barren reddish landscape.

The giant volcanoes of Hawaii’s Big Island held a special place for the Polynesians who first settled there, with the peak of Mauna Kea being reserved for that society’s elite. But in recent years, they’ve become home to a new kind of elite: some of the best telescopes humanity has designed. For the past several years, those legacies have clashed through a mix of protests, hearings, and legal maneuvers.

Scientists wanted to build one of our next-generation giant telescopes on Mauna Kea and received approval from the state to do so. But native Hawaiians and their supporters, disturbed by the ever-growing population of observatories and poor past stewardship of the mountain, protested and appealed. Now, the state’s Supreme Court has issued what appears to be a comprehensive ruling that upholds the latest construction approval from the Board of Land and Natural Resources. This appears to clear the last hurdle astronomers faced before starting construction.

A contentious history

Scientists have been building telescopes with state approval on top of Mauna Kea for decades, despite its significance to the Polynesians who first settled the islands. Over time, however, three trends set the stage for the current controversy. One was that a telescope, once built, tended not to come down, and the people doing the building didn’t always plan to keep the hardware unobtrusive or minimize the environmental damages of construction. At the same time, cultural awareness among those who could trace their ancestry to the first Hawaiians increased, as did our knowledge of their political and religious practices. Work on Mauna Kea identified many shrines and features that are of cultural and/or religious significance.

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Building the world’s highest-resolution telescope

If Lowell Observatory’s Gerard van Belle gets his way, you’ll soon be watching an exoplanet cross the face of its star, hundreds of light-years from the Earth. He can’t show you that right now, but he should be able to when the new mirrors are installed at the Navy Precision Optical Interferometer in northern Arizona. They’re arriving now and should soon start collecting starlight—and making it the highest-resolution optical telescope in the world.

Van Belle recently showed Ars around the gigantic instrument, which bears almost no resemblance to what a non-astronomer pictures when they hear the word “telescope.” There are a couple of more traditional telescopes in dome-topped silos on site, including one built in 1920s in Ohio, where it spent the first few decades of its life.

Going big

The best way to improve imagery on these traditional scopes is to increase the diameter of the mirror catching light. But this has its limits—perfect mirrors can only be built so large.

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Interstellar visitor might be a comet covered in carbonaceous crud

When the object 1I/2017 U1 ‘Oumuamua was first picked up by telescopes in October, there was no question that it was an odd duck—and that’s saying a lot considering that we recently explored a comet that looks like a duck. ‘Oumuamua seems to be a momentary visitor from another star system, punching through the plane of our Solar System from “above” like it hadn’t read our traffic signs. Oh, and it’s shaped like a cigar.

The list doesn’t end there. While it’s incredible to identify something that isn’t from our Solar System, it’s not a shock that such wanderers exist. Models of star and planet formation show that the growth of gas giants from the rotating disk of rubble that makes up an infant star system could easily fling some objects out into interstellar space. And since gas giants form beyond the “snow line”—the distance from the star at which water can exist as ice—most of these exiles should be comets, which are composed primarily of ice and dust rather than solid rock.

But while ‘Oumuamua passed fairly close to the Sun, it showed no signs of the long tail that comets usually sport as warm sunlight turns ice to vapor. And that means there’s no ice on its surface. So what is it?

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