About half of the light in the Universe is hidden behind clouds of cosmic dust, and humanity still cannot reach it. To change this, scientists are designing AtLAST—a 50-meter-diameter submillimeter telescope, the largest of its kind. It will run exclusively on renewable energy.
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What prevents us from seeing?
Dust in the centers of galaxies absorbs and scatters visible light. This means that most regions of active star formation—and entire galaxies—remain virtually invisible in the usual wavelength ranges.
Submillimeter waves—that is, radiation between radio waves and infrared light—help us see through the dust. In this range, cold dust and gas become transparent, revealing what lies beyond them.
How is AtLAST different from ALMA?
Currently, the primary instrument for such observations is the large South American Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which consists of 66 antennas. It works on the same principle as a microscope: it provides a very detailed but narrow view—in a single observation, it covers a section of the sky that is thousands of times smaller than the visible disk of the Moon.
AtLAST will take a fundamentally different approach. In a single observation, it will cover an area equivalent to 16 full moons, allowing it to systematically map large sections of the sky and detect objects that ALMA simply cannot detect.
Design and location
The telescope’s primary mirror, with a diameter of 50 meters, will be constructed from aluminum panels mounted on a massive steel support. The total weight of the structure is approximately 4,400 tons. A wide field of view will be provided by an additional 12-meter secondary mirror, which is larger than the mirrors of most telescopes in the world.
The telescope will be located near ALMA on the Chajnantor Plateau in the Atacama Desert, at an altitude of over 5 kilometers. There, the dry, thin air provides an exceptionally clear “window” for submillimeter observations.
Powered by clean energy
The project calls for the telescope to operate entirely carbon-free. Power will be supplied by solar panels and battery systems, and the telescope’s kinetic energy will be converted into electricity during deceleration after rotation—using the same principle as in a hybrid car.
The steel and aluminum for the structure are planned to be produced using virtually carbon-free energy. In this way, AtLAST could serve as a model for future large observatories.
What will the telescope be looking for?
Over 1,000 hours of observation, AtLAST is capable of detecting up to 50 million galaxies that are currently “hidden” within dust clouds and cannot be distinguished. The telescope will also help map the distribution of cold and hot gas around galaxies—matter that has so far been difficult to detect in sufficient quantities.
Other targets include molecules that may serve as the building blocks of life, as well as short-lived phenomena that are only observable in the submillimeter range. The telescope is designed to operate for 50 years, with the option to upgrade its equipment.
An international team from Europe, Chile, Japan, Canada, the United States, and other countries is currently working on the design phase, which will continue through 2028.
According to phys.org