Photograph by Dave Yoder
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Antennas forming part of the Atacama Large Millimeter/submillimeter Array (ALMA), high in Chile’s Atacama Desert, peer into the heavens.
Photograph by Dave Yoder

Dave Yoder: Painting the sky from the Atacama Desert

The largest-ever astronomical project, ALMA, is a herculean cooperation between three continents—North America, Europe, and East Asia—to build and network 66 radio antennas at 16,500 feet altitude in the Atacama Desert in Chile. The expansive radio telescope array, completed in 2013, is capable of scanning wavelengths that have seldom been explored. It searches the heavens for clues about the origins of the universe.

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ALMA (Atacama Large Millimeter/submillimeter Array) radio telescope antennas on the Chajnator Plain at 16,500 feet, with the dormant volcano Licancabur in the background.

A few months ago I stood alone in that Alice in Wonderland garden of high-science, surrounded by ALMA’s ginormous mechanical mushrooms, shuddering from cold and giddy from the rarified air. In the crystalline pre-dawn hours of a moonless night I watched antennas effortlessly pirouette, their silhouettes defined by a boisterous field of distant suns and galaxies. The light whistle of wind, blowing over the breach of the Chajnantor Plateau, smothered the faint hum of the antennas’ impossibly quiet magnetic motors to eerie effect. The dishes danced together in homage to the night sky, sometimes swinging about quickly, other times slowly, intently tracking distant curiosities.

I thought, “Remember this moment, Dave. You’re not likely to see anything like this again.”

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A view of antennas at the high AOS (Array Operations Site) site

Do we photographers go witness such things to take pictures, or do we take pictures in order to experience such things? I would not have been there had I not been on assignment for National Geographic magazine. In my case, I suspect the latter question is closer to the truth.

ALMA was experiencing growing pains during my visit. Frequent blackouts crashed their supercomputer, called the Correlator, one of the world’s largest. Antennas were often frozen all night, not only complicating my work, but more importantly, hemorrhaging precious observation time for disappointed astronomers.

It was during such down time that I approached antenna production manager Bill Johnson with a scheme to mount a camera onto the lip of an antenna dish. I took him three proposals. He accepted one. Our next step was to convince the ALMA administration.

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Burros are witness to an antenna being transported to the high AOS site at 16,500 feet elevation.

The safety rules at ALMA trump everything else. My first stop for every shoot on this assignment was always the safety department, because if it didn’t pass muster there, it was DOA. Thankfully, the safety officer I worked with on most requests, Ivan Lopez, was an ebullient anti-bureaucrat who didn’t unnecessarily toss around the word “no” as a privilege of position, something I had grown accustomed to from living in Italy. As long as safety issues were satisfied, he was usually game.

The biggest hurdle was that Bill and I would have to ride in the cabin of the antenna all night, during operation, to operate the camera and pan-tilt head. We explained that we would always be in radio contact with ALMA security over Bill’s radio, as well as with my assistants outside the antenna with another set of radios I had brought. It was green-lit, but I didn’t know that to another branch of the administration I had never met, such an operation was so wildly prohibitive that apparently nobody had thought of actually disallowing it.

In the perfect world that exists only in my head, I planned to take long-exposure pictures during the upcoming Geminids meteor shower, effectively turning the antenna into what an astrophotographer might consider a $7 million azimuth tripod. I hoped that long exposures of several minutes would collect the streaks of several meteors into a single image, while the antenna tracked a distant point in the sky to counter the rotation of the earth and minimize star trails.

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Antennas peer into the heavens.

On the day of the shower, a high-level administrator learned of our plan and promptly killed it. Rather than spending the day in preparation for the shoot, I navigated political channels to resurrect the project. It was ultimately allowed to proceed, but with the odd assurance that I had an exclusive, because they “will never allow anyone to do this again.”

Bill shut the cabin door of the antenna, which seemed rather like a space capsule inside. As he tilted the antenna skyward, the wall turned into the ceiling, and the door became a hatch above us. My laptop slid away from me as the floor transformed into a wall.

We were hardly settled in before the radio crackled; my assistant Pete Wintersteller, excited, was seeing meteors in the night sky. Within minutes, however, the temperature intercepted the dew point. To my horror, my laptop screen, which was monitoring the camera’s image in a live feed, turned milky-white. The lens had frosted over. It soon became clear the situation was hopeless as going to the camera in a man-lift at night was explicitly disallowed. As if matters weren’t bad enough, a radio then informed us that ALMA’s power had gone out again and the antenna was running on emergency generators. Bill’s eyes widened. “I’m taking it to zenith, let’s get out or we’ll be stuck in here for who knows how long.”

With the meteor shower lost, I spent the next day utterly deflated at the lower control site, wondering what to do. I had one more night at ALMA before the camera had to come down and I was scheduled to leave. I spied an ancient USB 1.1 coffee cup warmer on an electrical engineer’s desk. “Can I borrow that?” I asked.

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A photograph of star trails is captured from inside an antenna cabin.

A couple hours later at the AOS (Array Operations Site), as the cold afternoon winds buffeted Bill and me on the man-lift, we connected a second 20-meter USB cable to the coffee cup warmer and pressed it against the barrel of the lens, wrapping it in strips of torn blanket and tape. We clambered back into the antenna cabin, and as dusk retreated to reveal the stars, we proceeded to take clear, frost-free images. As he swung the antenna around, I made pictures with star trails. We watched movies on an iPad and munched on chocolate until dawn. Every half hour or so, our collaboration was rewarded with a new creation on the laptop screen, each one different from the last. Looking at the pictures we had made, Bill said, “I’ve been building these antennas for many years and I’ve never seen pictures like these.”

Dave Yoder’s photographs are featured in the April 2014 issue of National Geographic .