13,796-ft Mauna Kea, Hawaii's highest peak, isn't for the weak of heart. Literally. With atmospheric pressure 40% less than at sea level and less oxygen in your lungs there's headaches, sleepiness, nausea and clouded judgment. It's not for pregnant women, children under 16 and those with heart or lung problems. Many rental car companies don't allow their vehicles on the road up the mountain. An unpaved stretch of Observatory Road between visitor center and summit begs for 4-wheel-drive vehicles. Weather changes rapidly at higher elevations, with 100 MPH winds and whiteouts from blowing snow possible. A trip up Mauna Kea (White Mountain) isn't your typical day in tropical paradise. Why leave beaches for thin air? Mauna Kea, unlike anywhere else, is the world's greatest place for astronomy, above 40% of Earth's atmosphere and 98% of its water vapor. Mauna Kea's height and distance from worldly lights let astronomers see galaxies 12 billion light years away. Public stargazing is offered Thursday through Sunday nights. The 9,300-foot Onizuka Center for International Astronomy Visitors' Information Station, named for Hawaiian astronaut Ellison Onizuka, killed in the 1986 Challenger disaster, opens on these days.
Space junk
The center offers a jumbled collection of telescope parts, posters, space junk and videos. Cast-off clothes, mostly jackets, are for people wandering up there in shorts and Hawaiian shirts. 85 degrees on the Kailua-Kona coast change to 35 degrees on Mauna Kea. 8 miles from the visitors' center, including 5 miles of dirt and gravel road, an otherworldly landscape appears, volcanic and desolate, with snow wherever the sun doesn't shine brightly. Red and black volcanic dirt plus the dozen or so telescope buildings in all shapes, sizes and colors resemble Mars in a 1950s sci-fi movie.
Getting less disoriented
These foreboding fortresses, the complete silence and lack of vegetation, are eerie. It could be the thin air. The telescopes are several stories high, built 1968 - 1999, including optical, infrared and millimeter/sub-millimeter telescopes and the Very Long Baseline Array. Without brochures visitors are clueless. Most have no signs and none welcoming the public, except the W M Keck Observatory containing the twin Keck I and Keck II, 10-meter, 36-mirror telescopes seeing far into space's vast recesses. Keck's public gallery has brief visual explanations of the telescopes and photos they took. Despite clean restrooms you still feel like an interloper, with no guides or guards. Opening doors led to a cavernous room holding one of the Keck telescopes. Machinery, supplies and equipment on the concrete floor convince you you shouldn't be there. Snap a few photos and head back out into the cold. Summit tours are available on weekends, weather permitting, giving a much clearer picture of work done there.
Above the clouds
Mauna Kea offers stunning vistas of clouds below. Above it's clear. Despite warnings of impending doom the only effects of Mauna Kea's height is unsteadiness when exiting your car, like one mai tai too many. The cold air quickly sobers you. Keep the window open to acclimate to the thin air. Spend a half hour at the visitor's center. Drink lots of water. 55-mile Saddle Road, named for the plateau's shape between long-dormant Mauna Kea and still active 13,680-foot Mauna Loa, extends from near the Kohala Coast to Hilo. A 4x4 Jeep Grand Cherokee rents for $120 a day including tax at Harper's near Kona International Airport or in Hilo. Harper's, the only way to Mauna Kea, knows why you're renting the vehicle. Harper's is serious about its cars. Rather than just tossing you the keys, you get a lecture. Employees watch you read the disclaimers. They roll a mirror under the Jeep to make sure the underbody wasn't damaged by previous renters.
The 150-mile round trip from Kona takes a long half-day to complete. This isn't poolside service Hawaii. Saddle Road has no gas stations, restaurants or stores. Phones and restrooms are few and far between. After passing through range lands you drive through the Pohakuloa U S Army Training Area where signs warn of live ammo. You might meet a caravan of military vehicles. Mauna Kea State Park, 5 miles west of the Mauna Kea turnoff, rents cabins. Well-maintained, it's a great place for hiking. Padlocked bathrooms make it less inviting. Landscape moves from paniolo pasture to barren desert to the Pacific's only glaciated spot. Views of Mauna Kea and Mauna Loa vary but these aren't dramatic peaks visually. Still, photographic opportunities are many. Wise travelers bring water, a cell phone, a picnic lunch and rolls of Kodak. When adventure travel means biking, snowboarding and hang-gliding, available on Mauna Kea, driving there and walking around qualifies, too.
Dreams of telescopes are as boundless as the universe. Wanting views of faint planets in faraway galaxies, and technical advancements making it possible, scientists compete to create mega-scopes of Jovian proportions. Bigger telescopes give more light to study objects fainter, farther away or with higher resolution. A gargantuan telescope built like the Kecks but 10 times larger, its primary mirror bigger than a football field, housed in a structure as big as Egypt's Great Pyramid, is named OWL, OverWhelmingly Large, and for its keen night vision. Space telescopes with multiple orbiting parts spread miles apart, with improved technology for single- and segmented-mirror designs on the ground, hook up several smaller scopes to work together. Current generation telescopes grow bigger and better, by science quests disagreeing on the most practical approach. Technological hurdles are believed solvable. With vast amounts of work and money it's not too soon to think about it.
The dream telescope could cost $300 - $400 million. Mounted on Mauna Kea or atop mountains in Africa or Chile it would gather 10 times as much light as each Keck and produce images 3 times sharper. Bigger telescopes do deep-space observation, freeing smaller telescopes for viewing nearer objects. Telescopes get bigger ever since Galileo Galilei first trained his 1 1/2-inch refractor on the heavens 4 centuries ago, using a design similar to telephoto camera lenses today. Modern observatories use Isaac Newton's reflector design: gather the image in a large, concave mirror at the base and reflect it back to viewers by smaller mirrors.
After 1948's completion of the Hale telescope on Mt Palomar in Southern California, with its 16 1/2-foot-wide mirror, gravity grounded dreams of bigger ones for decades. With large pieces of suspended glass gradually distorted by its pull, bigger mirrors eventually would be thrown out of focus. The Keck telescopes, built in 1991 and 1996, overcame that hurdle. Instead of one big piece of glass for the primary mirror they use 36 interlocking, individually suspended hexagonal segments each 6 feet across, with a common focus. Result: telescopes twice as large and as sharp as the Hale and over 3 times as big as Lick Observatory's 10-foot Shane reflector. In theory a much larger telescope could use more segments. The Keck telescopes prove segmented-mirror scopes work well, offering confidence of larger scopes. The OWL telescope would have over 2,000 7 1/2 foot segments.
Atmospheric distortion makes stars twinkle, pleasing poets and annoying astronomers. Observatories at high altitude where air is thinner minimize this distortion. Keck Observatory sits at a dormant volcano's 13,800-foot summit. Atmospheric blurs rob telescopes of their full potential for clarity. This motivated launching the $1.5 billion Hubble Space Telescope with its 8-foot-wide mirror in 1990. Orbiting above Earth, it's freed from atmospheric and gravitational effects plaguing ground telescopes. Succeeding Hubble, the next generation space telescope with a 26-foot-wide mirror would orbit beyond the moon. Even more far-out designs are possible in space.
While Hubble was built like reflector telescopes on the ground, designs are envisioned with separately orbiting parts miles apart, made of lightweight aluminum and plastic membranes. Such a design could greatly lower one of the biggest barriers to building space scopes: cost, 100 times that of similar telescopes on the ground. Taking advantage of space is to design for space, not take a ground design and figure out how to get it up there. Putting telescopes with a 26-foot and even a 328-foot mirror in orbit take advantage of the lack of gravity and wind, looking at concepts completely different from those on the ground. Some aren't convinced that space-based telescopes are the way to go. It's significantly less expensive on the ground, without astronomical launch, update and repair fees. One way to enlarge ground telescopes is to hook several together. The Keck scopes were designed for use in tandem. The European Southern Observatory has two of its four 26 1/2-foot telescopes at La Serena, Chile, working together, planning to operate them in unison. The drawback is it gathers less light than one big scope.
To that end the Japanese telescope Subaru debuted at Mauna Kea with a 1-piece, 27-foot primary mirror. 7 inches thick, it corrects gravity-caused distortions with 264 motors adjusting its shape to compensate. At $400 million - several times the $77 million of the second Keck scope, which is larger - that approach may not be feasible for larger designs. The Hobby-Eberly telescope at McDonald Observatory in Texas has a 36-foot mirror built with a spherical curve, its 91 identical segments set in a low-cost, fixed-angle mount. It cost $13 million. The National Optical Astronomy Observatories in Tucson consider a larger version. Its drawback is the spherical mirror shape limits the telescope's field of view. Its mirror's 30-foot effective area is why astronomers look to expand Keck's design instead. A newly developed computerized system could neutralize atmospheric blur and produce images as sharp as those from space.
Adaptive optics was first envisioned in the 1950s. Computer technology was too primitive then to make it a reality. It was revived in the 1980s as secret Star Wars technology and employed more recently to sharpen the focus of lasers. UC-Santa Cruz' center for adaptive optics is funded by the National Science Foundation, involving Lawrence Livermore and 8 other universities. Adaptive optics in Lick Observatory's telescopes made their big-telescope debut at Keck. Using a system developed at Lawrence Livermore, Keck's image is passed to a 6-inch, flexible mirror whose 349 pencil-like arms make hundreds of slight adjustments each second to correct atmospheric blur. Such technology is crucial to reaping the full potential of larger telescopes, from a 100-foot mirror to the OWL, a $1 billion project 3 times as large. Technology doesn't exist to build an adaptive-optics system for a telescope bigger than the Kecks. Such a device requires thousands of tiny correcting arms, not just hundreds. Technical hurdles are a good reason to work on more modest proposals. Adaptive optics technology for such a telescope will be ready in the not-too-distant future, by the time the telescope is.