An international team of scientists, led by Europeans, is advancing in the construction of AtLAST, a submillimeter telescope that will allow us to observe what is hidden beneath the dense clouds of dust that “blur” much of the Universe from the largest astronomical project in the world.
No one erased half the cosmos, but those opaque layers prevent most instruments from clearly seeing the regions where stars are formed. While telescopes like ALMA focus on very small areas of the sky, AtLAST will function as a wide-angle telescope capable of covering much larger areas.
The project involves countries such as Chile, South Africa, Canada, Taiwan, Thailand, New Zealand, Japan, and the United States. It features a main parabolic antenna with a diameter of 50 meters and a secondary mirror of 12 meters, all with a reinforced steel structure and aluminum panels.
Key advantages over other observatories
AtLAST will be located in the Atacama Desert in Chile, at an altitude of about 5,000 meters, the same privileged location where ALMA operates. There, the thin atmosphere, lack of light pollution, and dry climate facilitate submillimeter observations.
The big difference lies in the field of view. While ALMA, with its 66 antennas, acts like a microscope analyzing regions thousands of times smaller than the Moon, AtLAST will be able to capture an area equivalent to 16 full moons at once. This makes it a unique tool for mapping large portions of the sky.
Submillimeter telescopes detect waves with lengths below one millimeter, from far-infrared to microwaves. They are the only ones that penetrate the densest dust clouds. Although the James Webb can see something in near and mid-infrared, it does not reach the wavelengths that AtLAST handles.
The hidden secrets beneath the dust
Under those clouds lie the stellar nurseries, where clouds of gas collapse and give rise to new stars. Observing these processes with greater precision will allow for a better understanding of the evolution of the Universe, the role of dark matter in its expansion, and even how life might arise in space.
AtLAST is expected to detect up to 50 million galaxies in just 1,000 hours of observation, something that other instruments cannot achieve with the same clarity in distinguishing one galaxy from another.
Another notable feature is its environmental commitment. It operates on renewable energy, primarily solar, stored in metal hydride batteries. Additionally, it harnesses kinetic energy by slowing its movements, similar to a hybrid vehicle, avoiding the use of fossil fuels. The carbon footprint in the acquisition of aluminum and steel has even been minimized.
The future of submillimeter observations
This telescope marks only the beginning. It is expected that by the 2040s, several instruments of this type will be operating. Although there is still no exact start date, it is estimated that AtLAST could begin functioning around the 2030s if everything goes as planned.
When it comes into operation, it will open a new window to study how stars form and how the cosmos has evolved. Scientists hope for answers about fundamental processes that until now remained hidden by those pesky interstellar dust clouds.
The Atacama Desert continues to establish itself as one of the best places in the world for astronomy, and projects like this reinforce its key role in advancing our knowledge of the Universe.
