At the End of the Earth, Seeking Clues to the Universe
The same conditions that make the Atacama, Earth’s driest desert, so inhospitable make it beguiling for astronomy. In northern Chile, it is far from big cities, with little light pollution. Its arid climate prevents radio signals from being absorbed by water droplets. The altitude, as high as the Himalaya base camps for climbers preparing to scale Mount Everest, places astronomers closer to the heavens as they study the origins of the universe.
Opened last October, the Atacama Large Millimeter/submillimeter Array, known as ALMA, will have spread 66 radio antennas near the spine of the Andes by the time it is completed next year. Like other radio telescopes, ALMA does not detect optical light but radio waves, allowing researchers to study the origins of the universe that are dark, like the clouds of cold gas from which stars are formed.