In the high-altitude desert of northern Chile sits the Atacama Large Millimeter/submillimeter Array (ALMA). Conceived as a partnership among scientists in Europe, North America, East Asia, and Chile, ALMA was designed to be a powerful radio-astronomy observatory that could peer into the coldest and most distant regions of the cosmos, where stars and planets are born.
What is it?
A recent post on X from the ALMA Observatory shows one of the telescope’s antenna dishes under construction, with the caption: “Fifteen years ago, when the antennas … arrived to Chile, they were assembled on site, piece by piece.”
Work on ALMA began in the early 2000s, and by 2011 the array of antenna dishes began early science operations. The site was chosen for its dryness and altitude, with little light pollution. The thin air allowed for millimeter and submillimeter wavelengths of light, which are normally absorbed by Earth’s atmosphere, to reach the antennas with little interference.
Where is it?
This photo was taken in an assembly warehouse near the Chajnantor Plateau in Chile, where ALMA is located.
Why is it amazing?
Rather than relying on a single telescope, ALMA is composed of 66 high-precision antennas, each either 23 feet (7 meters) or 39 feet (12 m) in diameter. These antennas can be moved across the plateau using massive transporter vehicles, adjusting the configuration of the array. When spread apart, these dishes act together as a single giant radio telescope with incredible resolution.
Unfortunately, having such a wide array can also have its drawbacks, as a recent snowstorm blanketed the area with unprecedented moisture. The observatory was forced to enter “survival mode,” with scientific observations temporarily suspended. Thankfully, the snow eventually melted and measurements could resume at this cutting-edge observatory.
Want to learn more?
You can read more about ALMA’s findings and telescopes in Chile.