The Atacama Desert in Chile is on the wrong side of the Andes.
The trade winds that might bring moisture from the east get
caught in the mountains instead, making this the driest place on
Earth. But this turns out to be perfect for the Atacama Large
Millimeter Array—the most powerful telescope in history. At
5,000 meters—about as high as Everest Base Camp—the atmosphere
is thin, and the heavens seem near. The Chajnantor Plateau of
the Atacama dwarfs the radio telescopes of ALMA, a project that
began construction nine years ago and is still in progress.
ALMA, a collaboration among scientists and governments from
Europe, Asia, and North and South America, aims to gather a
fuller view of the universe than has ever before been possible.
Scientists and engineers work in the control room at ALMA. Radio
frequencies received by the antennas are translated into data
and carried by fiber-optic cables to the operations support
facility. Because the site’s altitude is so inhospitable, the
project’s roughly 600 workers—sc