Listening to the Stars in Chile
Listening to the Stars in Chile
At 5,000 meters (16,400 feet), the arid Chajnantor Plateau in northern Chile would seem to have little to recommend it. Almost nothing grows in the cold, thin air three miles above sea level, and without an auxiliary oxygen supply normal human activity is impossible. Quick-moving blizzards in winter can be lethal.
Yet the expansive mesa and the barren Andean mountains that stand guard around it have been the winners of a string of beauty contests, of sorts, in recent years. Astronomers and physicists have repeatedly chosen this wilderness to locate some of the world’s most technologically advanced observatories.
An October visit to the Atacama Large Millimeter/submillimeter Array, or ALMA, which sits on the harsh plateau, reminded me of the importance of Chile’s institutional framework to economic development.
The land may seem useless, other than for mining. But thanks to political stability and the rule of law, creative minds backed by big investors—public and private—have discovered its comparative advantage as a giant laboratory to study the universe and its origins. As a result, a small, mountainous country on the edge of an otherwise struggling continent is fast becoming a magnet for astronomers the world over.
I took the two-hour flight to the northern mining city of Calama from Santiago and the 90-minute car ride to the oasis town of San Pedro de Atacama because I wanted to stargaze. But I got much more. Mystics always seem to flee into the desert for spiritual retreat, and the stark Atacama, with its still saltwater lakes, exotic wildlife and sunsets to make you cry, reminds visitors of why that is so. So too does the glorious night sky.
Perhaps it’s the simplicity of the desert that unleashes the inner metaphysician in so many people. But I think it’s the wideness of the sky next to the nakedness of the land. The emptiness taps into that primordial yearning to discover ourselves by discovering our place in the universe.
As science forms a consensus that there is no better place on the planet than northern Chile to engage that search, the potential for the country is soaring. Alvaro Fischer, president of the Santiago-based Science and Evolution Foundation, told me in a telephone interview last week that “by the end of the decade [northern Chile] could have two-thirds of the world’s data-collecting capability in astronomical terms.”
This is no accident. The view from the Atacama Desert is super clear because it is among the driest places on earth. And ALMA says its observatory is “above some 40% of the atmosphere.” I needed to pass a blood-pressure test before going to the summit. It’s not open to the public, but a visitor’s center at 2,900 meters is expected to open in early 2015.
The north of Chile is already home to the European Southern Observatory’s powerful Very Large Telescope. The Giant Magellan Telescope is a work in progress by an international consortium. Another on the way is called the European Extremely Large Telescope. It will have a 39-meter main mirror and will be the largest optical telescope in the world. The European Southern Observatory says it will be “the world’s biggest eye on the sky.”
Still, only a small slice of the electromagnetic spectrum can be seen, even with high-power lenses. That’s where ALMA, which is funded by the U.S., Europe, Japan, Canada and Taiwan, comes in. Using 66 dish antennas weighing up to 100 tons each, the telescope can capture light found on the spectrum between the far infrared and radio waves. As one San Pedro local whispered to me, with a twinkle in her eye, when I asked her what they do on the plateau: “They listen to the stars.”
Cal Tech and Cornell University are leading a consortium to build the Cerro Chajnantor Atacama Telescope, or CCAT, above the plateau, at 5,600 meters (18,373 feet). Like ALMA it will study nonvisible activity in the cold, dark parts of space.
But ALMA is different. Thanks to the sweeping tabletop and two large transporters, named Otto and Lore, ALMA says scientists can reposition their 66 antennas “across up to 16 kilometers of level ground.” Placing the antennas close together provides the best picture of “large-scale features” of the subject being studied. “When they are spread far apart,” the array “can see with the highest resolution.”