Llano de Chajnantor Observatory

The observatory comprises 64 transportable antennas measuring 39 feet (12 meters) in diameter, distributed across 8.7 miles (14 kilometers) of desert terrain at 16,400 feet (5,000 meters) elevation. The antennas can be reconfigured as needed to create different astronomical arrays and capture radio waves from space.

In 1999, the Cosmic Background Imager became the first radio telescope to conduct observations under the skies of Llano de Chajnantor. Construction of the current facility began in 2003 as a joint project between East Asia, Europe, and North America. First scientific observations started in 2011, followed by official inauguration two years later.

Scientists from Japan, Europe, and North America work at this facility, advancing astronomical research through international cooperation that expands knowledge about star formation and galaxy evolution. The installation contributes to Chile's position as a global center for radio astronomy and millimeter-wavelength observation.

The facility offers guided tours on weekends between 9:00 and 13:00, with transportation provided exclusively by buses due to altitude considerations. Visitors must register online at least two weeks in advance and consider health restrictions related to elevation. Warm clothing and sun protection are required for the tour.

The location provides optimal conditions for submillimeter astronomy, with exceptionally dry air present more than 300 days per year and precipitation below one millimeter. These atmospheric properties enable observations at wavelengths that would be blocked by water vapor at most other locations on Earth.