STARGAZING IN HIGH-DEF

One wind-swept and moonless night two years ago, I stood near the summit of Cerro Tololo in the Chilean Andes and wondered, Where are the stars? I knew they were out there. A cluster of sloe-eyed international observatories crowded the mountaintop to take advantage of the altitude, dark skies and remarkably transparent air--what astronomers call, with the light touch of poetry, the “seeing.”

And yet, this sky was all but black. I could make out a few familiar faces--Sirius, Polaris, Mars, Jupiter and Alpha 1 Crucis, the teasing kite-tail star of the Southern Cross--but beyond these brightest objects, little penetrated the night. I stood there with my eyes shut, wavering in the sideways gusts, hoping my vision would adjust. But it never did. This was a special kind of black, sullen and ungovernable, the blackness of blindness, of severed optic nerves and sudden trips to the boxing-ring canvas. I had no idea what was going on.

I didn’t find out until a few months ago, when I was at a party in Pasadena chatting with an astrophysicist from the Jet Propulsion Laboratory. “You were oxygen-deprived,” he said. Cerro Tololo is about 7,000 feet, high enough that the astronomers who work there carry oxygen in case they start to feel lightheaded. “You should try that sometime with a bottle of OA²,” he said. “Take one breath and the stars just”--he reached out as if grabbing the sky and drawing it to his face--”whoop, leap out at you.”

Oh yeah, I thought. I’ve got to try that.

I am not typically a sleep-by-the-pool vacationer. If I go somewhere, I usually have a quest in mind (this might be a good time for the reader to make a mental note not to vacation with me). And the oxygen-and-night- vision thing wouldn’t go away. What are the possibilities? Where, on balance, is the best place in the world to practice oxygen-enriched stargazing? Given the apparent inverse relationship between altitude and vision--the excellent seeing of high mountains being negated by increasing night blindness--and the difficulty of transporting bottled oxygen, I needed a compromise, a place that was very high but also easily within reach, very dark but still near civilization.

I’d already been to such a place: Mauna Kea, a 14,000-foot dormant volcano on the island of Hawaii. Mauna Kea is home to the Keck Observatory and a host of other advanced telescopes. No more than two hours’ drive from Kailua-Kona on the western shore, or Hilo to the east, the summit of Mauna Kea is renowned for some of the best astronomical seeing on the planet.

I booked a ticket to Kona and started researching the oxygen-vision connection. Apparently, it’s well known among pilots, who are encouraged to use supplemental oxygen at night in unpressurized planes as low as 5,000 feet. Even at that altitude, “your night vision drops off dramatically,” says Dr. Gabriel Travis, professor of ophthalmology at UCLA, who is also a pilot.

The photoreceptors in the retina are among the most metabolically active cells in the human body. It takes an enormous amount of energy--which is directly related to cellular oxygen demand--for these light receptors to work in the dark. The biochemistry is complicated, but Travis compares these cells to boats “with bailing pumps running all the time.”

At higher altitudes, these photoreceptor cells struggle to keep up, and they start signaling as if there’s a background light on. “It’s not the stars you can’t see,” Travis says. “It’s that you can’t see the black.”

At 14,000 feet, there is 40% less oxygen than at sea level--and roughly that much less receptivity in the eyes to light. Clearly, I needed oxygen. For obvious safety reasons you’re not allowed to take compressed gases on an airplane, so I ordered a 40-minute bottle of emergency OA²--the sort of nonprescription unit you might find in a good first-aid kit--from Life Corp. in Milwaukee. I paid extra to have it express-shipped to my hotel on the Big Island.

That was a mistake. Of course, without mistakes, it wouldn’t be a quest.

The night sky that hung over the Israelites on their walk from Egypt, the starlight that guided Leander as he swam the Hellespont and lured Galileo into apostasy, they are all but gone now, swamped by atmospheric pollutants and scattered urban glare. Experts say the latter half of this decade will mark the first time in history that more humans will live in urban areas than in rural areas. It stands to reason that as the Earth brightens and more people crowd under domes of reflected urban light, the fixtures of the night sky will become less and less familiar. When you consider the historical importance of stars as auguries of the future and shapers of destiny (astrology), as tools of navigation and keepers of the agrarian calendar, their decline is an unsettling development.

In any event, the fully lighted night sky--the diamond-dusted, blue-black firmament that our ancestors needed only to look up at to see--is a fairly exotic sight these days, and full of surprises. It is, for example, rich with color-- pinpoints of red and orange and blue and violet-white. And, rather than being some slow-grinding celestial cinema, it bustles with movement. City dwellers can’t appreciate just how many meteors streak through the atmosphere on any given night, and some man-made objects, like the International Space Station, are so big and so bright that they barrel across the sky like runaway buses.

All these fireworks are visible to the naked eye, under the right conditions. More profound, perhaps, given our current understanding of cosmology, is the night sky’s humbling tableau of time and distance. A few years ago, I was camping in Wadi Rum--the picturesque sandstone canyon in Jordan where David Lean filmed “Lawrence of Arabia”--and watched as the hazy disc of the Milky Way (our galaxy) tilted under the horizon to the west. Then, with a terrible immensity, the cloudy center of the galactic plane rose in the east. I could see it all, as if in some peyote-fueled revelation. The Earth is a mote of dust caught in the gravitational slipstream of an ordinary star, swirling around with 200 billion or so other stars in a spiral galaxy about 100,000 light-years across. One galaxy is incomprehensible. There are more than 80 billion galaxies in the observable universe.

And to think I worried about my credit card bill.

My oxygen hadn’t arrived at the hotel in Kailua-Kona. A few phone calls later, I was told the hazardous materials manifest had been filled out incorrectly and Aloha Airlines had declined to transport the package from Honolulu. It would take another week to correct the paperwork. I could blame the punctilious Transportation Security Administration, or I could blame an overworked and indifferent pilot flying freight for the recently bankrupt Aloha Airlines--and I did--but either way, I wasn’t getting my bottle of OA².

The weather atop Mauna Kea had been dicey--unusual, because the peak is well above the clouds most of the time--and I had only this particular Friday night to work with. Thinking fast, I decided to rent scuba gear from one of the local dive shops, reasoning that breathing regular air (oxygen at sea-level pressures) would at least be better than Mauna Kea’s ambient atmosphere.

To reach Mauna Kea you have to drive the island’s Saddle Road, which varies from a broad and perfect highway to a crumbling one-lane roller coaster of asphalt, until you reach the turnoff for the mountain. From there, it’s a steep, narrow and winding six-mile drive to the Mauna Kea Visitor Information Station, at 9,200 feet. If you plan to continue to the summit, on the rather intimidating gravel road, you need a four-wheel-drive vehicle. Visitors are not usually allowed on top after sunset because of the hazards of negotiating the 20% downhill grade in the dark while addled by thin air. Even with the benefit of daylight, auto accidents are routine.

But I had used my journalistic clout to get permission to stay on the summit after dark. At 7 p.m. I was sitting in the front seat of my rented Ford Expedition with a scuba tank beside me, sucking on the regulator hopefully, as I watched the last of the Japanese tourists climb back on their buses and head down the mountain. Sunset on snowcapped Mauna Kea is its own celestial dance, as our home star settles and simmers into the clouds. You can almost feel the Earth rotate beneath you. One by one, the observatories opened their eyes to the sky.

And then the stars came out. Sort of.

Granted, conditions were not perfect. High cirrus clouds meandered across the stratosphere. A half-moon blazed away high overhead, bright enough for me to see the ghost-blue domes of the observatories. Even so, the stars did not seem particularly bright--despite the fact that I was huffing and puffing on my scuba tank for all I was worth. I felt kind of awful.

The blackness was back. I could hear the observatories’ domes slueing around, a baleful motorized sound that reminded me of hounds on the moor. They had to be looking at something. But I could barely make out the major constellations and, as for the sky-spanning wash of scintillation, the Milky Way, there was nothing. Where was the gyre of creation?

Maybe the oxygen thing didn’t really work after all?

Disappointed, cold and kind of loopy, I slowly drove down the mountain until I reached the visitors station. Here, every night of the year, volunteers bring out the center’s array of telescopes--including some enviable professional-grade 16-inch instruments that they hook up to computer displays. As I got out of the car I realized the stars were drastically brighter than they had been on top of the mountain. What the hell?

I explained my scuba-air experiment to one of the volunteers, Norman Purves, a physics and astronomy professor at the University of Hawaii-Hilo. He seemed amused.

“I’m afraid it doesn’t work that way,” he said. “Your body absorbs oxygen depending on partial pressure, a function of the ambient pressure.” Even though I was inhaling sea-level air, Purves explained, I was absorbing only 60% of it. My scuba rig had done nothing beyond making me hyperventilate.

“But pure oxygen works great,” Purves said. Then you’re getting 60% of 100% percent oxygen, or three times the oxygen in sea-level air. “You’ll have to come back and try it again.”

I hung around the visitors station, as if loitering would damp my sense of foolishness and wasted time. One volunteer, in particular, seemed eager to make my trip worthwhile. Clifford Livermore, a retiree and devoted telescope bug, took me on a consolation tour of the universe, using an astonishing light-gathering eyepiece fixed to the center’s 16-inch scope: Carina Nebula, the Sombrero Galaxy, the Omega Centauri Globular Cluster, the Jewel Box cluster.

We stood out on the lanai until the custodians starting packing up the telescopes. And even then we talked stars, kicking rocks in the parking lot. “I just love this so much,” said Livermore, a big, shambling figure in a parka, a strange, mounded silhouette in the dark. “I’ve been thinking about time and the stars all my life. It’s like music. You either get it or you don’t.”

“You don’t do astronomy with your eyes,” he said quietly. “You do it with your heart and soul. You can see so much more.”

And all I brought was bottled air.

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(BEGIN TEXT OF INFOBOX)

Guidebook

How to Get There

Kona International Airport is in Keahole, north of Kailua-Kona. Options have narrowed with the loss of Aloha Airlines, but United, American, Alaska Airlines and USAir still fly direct from LAX.

Where to stay

Dragonfly Ranch, P.O. Box 675

Honaunau; (808) 328-2159, www.dragonflyranch.com. Billing itself as a “healing arts retreat,” this rustic, cottage-style B&B; seems to be located in the middle of a giant monkeypod tree. The “Fly” is unspeakably relaxed and puts you in the perfect frame of mind for stargazing. On Highway 160, on the way to Pu’uhonua o Honaunau National Historic Park.

Where to eat

Teshima’s, 79-7251 Mamalahoa Highway, Kealakekua (at the intersection of Mamalahoa Highway and Highway 11); (808) 322-9140. Teshima’s family restaurant has served the island’s Japanese population for generations. Always crowded but worth the wait. Open for breakfast, lunch and dinner, when you can get the Bento box carryout.

oxygen supplies

By prescription: It may be possible to get a doctor’s prescription for OA² and have it filled at a medical supply store.

Retail: Portable emergency oxygen units are for first-aid use.These devices qualify as hazardous materials and are difficult and expensive to ship by air.

On the mainland: You can use a variety of minicanisters of compressed oxygen designed for mountain sports.--D.N.