Mauna Kea’s Amazing Gazing

(Syndicated article for the Metro newspaper group).

The building that hosts the Gemini North telescope.
It's twin sibling sits on top of a mountain in Chile.
                                                        Photo: Hans Sandberg


At 13,796 feet, not much grows and the air is mostly clear. 
                                                                  Photo: Hans Sandberg

There is probably no better place on Earth for stargazing than on the summit of Hawaii’s Mauna Kea (Hawaiian for “white mountain.”) The long dormant volcano climbs 4,205 meters (13,796 feet) over the Pacific Ocean on the Big Island of Hawaii, and its clear and stable atmosphere has attracted the largest collection of telescopes in the world. Giants such as the Keck twin observatories, Gemini, and Subaru, are there to help us understand the birth of planets, stars and galaxies, and to search for celestial objects so far away that their faint light may reveal secrets about the beginning of time.

The island of Hawaii is the biggest and most southern of the state’s eight islands. It’s twice as large as all of the others combined, hence the nickname - “The Big Island.” It is also the youngest -- and still growing -- as nearby Kilauea pours huge amounts of molten lava into the sea on the island’s southern shore. Mauna Kea has not erupted in 3,000 years however, which explains why eleven countries dared over the last four decades to spend more than a billion dollars building thirteen telescopes on it’s summit.

Way up there, astronomers and their expensive telescopes may be safe from eruptions, but not necessarily from Mother Nature. It is not uncommon for winter storms to deliver winds reaching over 160 km (100 miles) per hour, sometimes dumping a thick layer of snow on the volcano’s peak. Most of the time however, it is not heavy winds, but the height of Mauna Kea itself -- with its cold and thin air -- that threatens human life, as well as most other life forms.

“If you drop anything when you are exiting the car, don’t pick it up,” says Peter Michaud, a press and community relations manager for the Gemini Observatory, which runs two of the most sophisticated telescopes in the world – one on Mauna Kea, the other in Chile. With 40 percent less oxygen to breathe, bending down can lead to fainting.

The trip from Hilo to Mauna Kea starts on Saddle Road – a roller coaster-like ride that becomes a bit nauseating after driving on it for an hour. Halfway to the other side of the island, another small road continues upward to the Onizuka Center for International Astronomy. At 2,800 meters (9,300 feet) above sea level, this quaint visitor’s center is named after the Hawaiian astronaut who perished when the space shuttle “Challenger” exploded in 1986, but is also known to the Hawaiians as Hale Pohaku (“stone house”). The view is stunning during the day, and evening stargazers are in for a treat – seeing the Milky Way as never before. Most tourists shy away from driving the extra 1400 meters up to Observatory Hill, which is at the end of a steep, narrow, eight-mile dirt road, and can be treacherous at night.

Since both the visitor’s center and the summit are open to the public, some experienced off-road drivers do take their four-by-fours up to the top (most car rental companies explicitly prohibit taking their vehicles anywhere near Mauna Kea,) but not before pausing for at least one hour at the Onizuka Center to allow the body to adjust to the high altitude. A dedicated weather and road condition telephone hotline is updated each day for potential visitors. Hale Pohaku also has a lodge that sleeps 72, and is used for astronomers and staffers who work on the summit during the night – so that they’ll have a place to rest during the day without having to repeat the altitude adjustment over and over again.

To prevent altitude sickness, it’s suggested that visitors don’t smoke, drink alcohol or coffee -- or go scuba diving -- the day before, and eat no heavy meals right before the ascent. Drinking a lot of water is also necessary to prevent severe headaches. Warm clothing (including hats and gloves) is a must, and like airline pilots who are exposed to strong sunlight in the upper atmosphere, extra strong sunglasses (preferably with UV-filters,) and sunscreen with a factor of at least 15, is needed.

It’s a lot to remember, especially for an oxygen-starved brain. Michaud warns that people become forgetful sometimes, and wander off aimlessly. That is, until they lose their breath, and their heart starts pounding like that of an 85-year old. A photographer visiting the summit admits to opening his camera without rewinding the film while on the summit, thereby ruining his entire photo shoot.

The landscape at the summit is completely barren, except maybe for black, gray, and rust colored stones. There are no trees, no bushes, no visible vegetation or animals - but for a stray mountain goat. The area is often compared to the planet Mars, and in fact, NASA used the area to train its Mars Lander equipment. Looking down, one can see several copper red cinder cones shooting up from the steep lava slopes. And peeking out from the clouds in the distance is the active volcano Mauna Loa (of macadamia nut fame,) and Haleakala (“House of Sun,”) a 3,049 meter (10,000 ft.) high volcano on the neighbor island of Maui.

Once the sun sets, the temperature quickly approaches the freezing level -- even during the summer months -- as there are few clouds to lock in the heat. This is good news for astronomers however, who would if possible, prefer do all of their observing from the crisp clarity of outer space.

Sitting above 40 percent of the Earth’s atmosphere, Observation Hill has few clouds, and benefits from strict local laws against light pollution on the sparsely populated island. Its location in the middle of the Pacific Ocean also creates an unusually stable and clean atmosphere (something that may not be obvious as you drive through the Kona district on the island’s west coast, where coffee growers complain that ashes from ongoing eruptions cloud the sky and block the sun.)

“There is no getting around the fact that the Earth’s atmosphere is a pain to have to work through,” says Matt Mountain, director of the Gemini Observatory. But if space observation has to be earthbound, Mauna Kea is the place to be.


Hans Sandberg (at Mauna Kea)

Stairway to the Stars

(Syndicated article for the Metro newspaper group).


Some of the telescopes at Mauna Kea's peak.

Interest in building an astronomical center on Hawaii caught on in the 1950’s, but the location of choice was Maui’s Haleakala, which had one thing the Big Island’s Mauna Kea did not have -- a road to the top. A solar observatory was built, but it soon became clear that Haleakala was not ideal, as clouds reached its summit, and its crater sometimes filled with fog that spilled over. Surrounded by fog, the scientists looked outward, and across the Pacific waters saw Mauna Kea rising tall above the clouds.

It took a lot more than clear air and a tall mountain to make a home for telescopes however, all of which is detailed in Barry Parker’s 1994 book Stairway to the Stars. Building on the mighty White Mountain took money and politics, as well as daring individuals willing to take risks. And in the case of Mauna Kea, tragedy also played a role, as the nearby city of Hilo was almost totally destroyed by a huge tidal wave on May 22, 1960.

With its capital city’s downtown in ruins, the mayor of Hilo began to look for new ways to generate income and jobs. Astronomy was one solution, and the governor of Hawaii was soon convinced to fund the building of a road up to Mauna Kea’s summit. (This decision would later translate into hundreds of new jobs and $80 million annually to Hawaii’s economy.)

The first big telescope to open on Observatory Hill was the 2.23-meter (88-inch) telescope built by the University of Hawaii, which opened in 1970, but wasn’t fully operational until 1976. In 1979, a 3.6 meter Canada-France-Hawaii telescope went into operation, followed by several more - including both infrared and radio telescopes.


The Keck Twins at Mauna Kea.  Photo: Hans Sandberg.

But the project that put Mauna Kea on the world map was the Keck observatory. This revolutionary giant telescope had a “honeycomb” mirror with a diameter of 10 meters (33 feet). Such a large disk would have been almost impossible to build and operate using the technology of the time: a single mirror. Keck designer Jerry Nelson instead opted for 36 smaller mirrors, which would all work together as one. To do this, it was necessary to develop a highly innovative system that could change the shape of every single mirror segment continuously, and then align them with extreme precision. This technology is called active optics (adjusting the shape of the mirrors.) By combining active optics with another new technology: adaptive optics (where computers calculate disturbances in the Earth’s atmosphere and “correct” them by continuously adjusting the telescope’s mirrors and lenses,) Keck began a new era for astronomers everywhere.

Behind the $76 million Keck project was the University of California and Caltech (California Institute of Technology,) and the Keck Foundation. Later on, the fund paid for a second Keck-telescope -- which today sits next to the first. The idea is to get them to function as a single telescope, thereby doubling the power. This technique -- which is common in radio astronomy -- is called interferometer. Since it is however much, much harder to perfectly match up optical images than it is radio signals, this goal has yet to be completed.

One problem that the new telescopes did not solve was the shortage of telescope time. Two-thirds of the observation requests made by astronomers were routinely turned down, which is why some of the world’s leading associations for astronomy proposed building two new large telescopes – one in the northern hemisphere and one in the south. The National Science Foundation (NSF), which funds most of the industry’s basic research in the US, financed half of the $176 million needed to build twin telescopes in Hawaii and Chile. Six other countries also funded the Gemini plan: Argentina, Australia, Brazil, Canada, Chile, and the UK.

Like Keck, Gemini broke new ground in many ways. They decided to use a single piece of glass, but a much thinner disk than those of previous generations. The 8.1 meter mirror is flexible, and is coated with a super-reflective silver solution, instead of aluminum. “Our thin mirror, which is basically a twenty-ton contact lens, no longer relies only on glass and steel to keep it aligned. Behind it, there are 120 computers, which constantly monitor the shape of the mirror, and adjust it as it moves across the sky,” says Matt Mountain, director of the Gemini Observatory on Mauna Kea. The result is a telescope that in some respects can match both the Hubble Space Telescope, and the Keck twins – a “fly-by-wire airplane” as Mountain calls it.

When completed in late 2001, Chile’s Gemini South will work with Hawaii’s Gemini North to give researchers a chance to study the entire hemisphere from remote locations - via super fast computer networks. “For example, the Magellan Cloud, our nearest galaxy, is not visible from the north. The center of that galaxy is very low down in north, and we have to look at a lot of atmosphere to see it, while in the south it goes straight overhead,” says Mountain. So theoretically, a team of observers -- one sitting in Brazil, one in Washington, and one in Hawaii -- can collaborate over a network using both telescopes. “It will be a long night if we get the right overlap, because you can get one twelve hour night, and then another seven hour (night) for certain parts of the sky,” he adds.

Gemini is designed to look far into the universe, and is especially good at capturing infrared light. Though infrared heat radiation is invisible to the human eye, it is tremendously important for modern astronomy. Infrared telescopes for example, can see right through the vast, dark clouds that obscure our view, and allow astronomers see the universe at its very early beginnings. “You can see into the heart of stellar nurseries, and can catch information about planets and planetary disks that you couldn’t catch (before.) You can also see into the heart of our own galaxy - to the galactic center where there is probably a black hole hidden,” says Mountain.

As telescopes get bigger and optics more precise, demands on the rest of the system increase as well. The machinery that moves the telescope and the dome, must do so without causing any vibrations. In an almost surreal act, Gemini’s 673-metric ton shiny silver dome rotates almost without a sound. Vertical “doors” open to expose the sky, while the rest of the dome splits horizontally in half and rises up in order to circulate the air. Another impressive sight is the cable room below the telescope, which holds its “spinal cord” in the form of hundreds of wires nested into dozens of thick bundles.

For an astronomer, it is essential to have good resolution as you focus on smaller and smaller objects. To give an idea of how sensitive the Gemini telescope is, Gemini’s Peter Michaud explains that it would be like seeing a pair of headlights on a car driving on the Golden Gate Bridge in San Francisco from the top of Mauna Kea 2,000 miles away. “That is assuming however, that the Earth had no atmosphere, and was completely flat,” adds Michaud.

As for the future, Matt Mountain foresees a new generation of 30 to 100-meter telescopes, one of which is actually slated to be built on Mauna Kea. This enormous telescope will however, be Mauna Kea’s last, he adds.

Hans Sandberg