Trucks stall on the road to this plateau 5,050m up in the Atacama Desert, where scientists are installing one of the world’s largest ground-based astronomical projects. Heads ache. Noses bleed. Dizziness overcomes the researchers toiling in the shadow of the Licancabur volcano.
“Then there’s what we call ‘jelly legs,’” said Diego Garcia-Appadoo, a Spanish astronomer studying galaxy formation. “You feel shattered, as if you ran a marathon.”
Still, the same conditions that make the Atacama, Earth’s driest desert, so inhospitable, make it beguiling for astronomy. Far from big cities, the Atacama has a dearth of 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.
Opened in October last year, the Atacama Large Millimeter/Submillimeter Array (ALMA) will have spread 66 radio antennas near the spine of the Andes by the time it is completed next year. Drawing more than US$1 billion in funding, mainly from the US, European countries and Japan, ALMA will help the oxygen-deprived scientists flocking to this region to study the origins of the universe.
The project also strengthens Chile’s position in the vanguard of astronomy. Observatories are already scattered throughout the Atacama, including the Cerro Paranal Observatory, where scientists discovered in 2010 the largest star observed to date, and the Cerro Tololo Inter-American Observatory, which was founded in 1961 and endured Chile’s tumult of revolution and counter-revolution in the 1970s.
However, ALMA opens a new stage for astronomy in Chile, which is favored by international research organizations for the stability of its economy and legal system. Like other radio telescopes, ALMA does not detect optical light, but radio waves, allowing researchers to study parts of the universe that are dark, like the clouds of cold gas from which stars are formed.
With ALMA, astronomers hope to see where the first galaxies were formed and perhaps even detect solar systems with the conditions to support life, like water-bearing planets, but scientists express caution about their chances of finding life elsewhere in the universe, explaining that such definitive proof is likely to remain elusive.
“We won’t be able to see life, but perhaps signatures of life,” said Thijs de Graauw, a Dutch astronomer and ALMA’s director.
Still, scientists believe ALMA will make transformational leaps possible in the understanding of the universe, enabling a hunt for so-called cold gas tracers, the ashes of exploded stars from a time about a few hundred million years after the Big Bang, that astronomers call the “cosmic dawn.”
ALMA’s construction, said Jesus Mosterin, a prominent Spanish philosopher who writes about the frontier between science and philosophy, and who visited the observatory last year, is taking place at “the only time in history that windows into the universe are being thrown wide open.”
Chile is not the only country luring big investments in astronomical projects. South Africa and Australia are competing to host an even bigger radio telescope, the Square Kilometer Array, which would be fully operational by 2024. China has begun building its own large radio telescope in a crater-like setting in the southern province of Guizhou.