A new European-led telescope could map the dusty, hidden half of the universe, all without using fossil fuels.<\/p>\n
If you have ever seen the Milky Way in the night sky, you probably noticed that it looks cloudy. That is because towards the centre of our galaxy, and of most galaxies, there are vast amounts of dust that make it hard to see what is going on.<\/p>\n
That means a big swathe of the universe is hidden to us, with about half of the light coming from galaxies buried in this dust. The best way to see inside these obscured regions is to use a gigantic submillimetre-wave telescope that\u00a0detects radiation\u00a0between radio waves and infrared.<\/p>\n
\u201cWithout submillimetre, we\u2019re getting a very biased picture of what\u2019s out there,\u201d said Claudia Cicone, an astrophysicist at the University of Oslo in Norway. \u201cWe are missing the regions of space that are most obscured by dust.\u201d<\/p>\n
In recent decades, telescopes like the Atacama Large Millimeter\/submillimeter Array (ALMA<\/a>) in Chile have allowed us to probe some of these regions.<\/p>\n Now astronomers want to go further with a new European-led project called the Atacama Large Aperture Submillimeter Telescope (AtLAST), a 50\u2011metre telescope\u00a0far larger than any submillimetre telescope built before.<\/p>\n Early design work is being\u00a0carried out in an EU\u2011funded project called AtLAST2<\/a>, which is running until 2028. Researchers from Europe and around the globe \u2013 Chile, South Africa, Canada, Taiwan, Thailand, New Zealand, Japan and the USA \u2013 are refining the concept by prototyping key technologies and planning how to run the facility as sustainably as possible.<\/p>\n The aim is to bring that cloudy, hidden universe into focus. \u201cWith previous submillimetre facilities, we\u2019re observing the tip of the iceberg,\u201d said Cicone, one of the leads on the telescope. Astronomers can today see only a fraction of the cold gas and dust that shape galaxies.<\/p>\n \u201cWith AtLAST, we will answer the question of where all the gas and dust in the universe is.\u201d<\/p>\n AtLAST is designed to slot into a new generation of giant observatories set to reshape astronomy in the 2040s, following Europe\u2019s Extremely Large Telescope<\/a>, which is nearing completion in Chile.<\/p>\n Without a large, single-dish submillimetre telescope like this, astronomers say there will be a major gap in our ability to map cold gas and dust across the sky and to link what these other facilities see at different wavelengths.<\/p>\n Wide-angle view<\/p>\n ALMA\u2019s 66 antennas in the Atacama Desert act like a microscope, giving focused views of dusty regions where stars and planets form. AtLAST, by comparison, would be a wide-angle camera, able to take a census of dusty locations across the universe.<\/p>\n \u201cALMA can only see an area thousands of times smaller than the Moon\u2019s surface on the sky in any given observation,\u201d said Tony Mroczkowski, an astronomer at the Institute of Space Sciences in Spain and another of AtLAST\u2019s leads.<\/p>\n \u201cALMA is powerful, but you can\u2019t map the sky with a microscope. In comparison, AtLAST will image an area up to 16 Moons in size with every observation, so we can map the hell out of the universe,\u201d he joked.<\/p>\n To map the sky at that scale, the telescope would\u00a0\u201cneed to move fast to map back and forth\u201d, said Mroczkowski. \u201cWith a huge field of view, we would create a pretty large map of the sky quickly.\u201d<\/p>\n The AtLAST2 team is using this design phase to prototype crucial parts of the telescope, from its optics and control systems to\u00a0its data handling.<\/p>\n Built to last<\/p>\n The primary 50\u2011metre dish of AtLAST would be designed with aluminium panels in the mirror and a massive steel backing structure. In total, it would weigh about 4 400 tonnes, and would include a\u00a012\u2011metre secondary mirror \u2013 itself larger than most telescopes \u2013 to help deliver\u00a0its wide field of view.<\/p>\n It would be located near ALMA in the Atacama Desert, where the thin and dry atmosphere at over 5 km above sea level allows a pristine view of the universe.<\/p>\n \u201cThe telescope would be entirely powered by renewable energies, using a novel, tailored hybrid energy regeneration,\u201d said Cicone. As the telescope slows after moving, its kinetic energy can be recovered as electric charge, like in a hybrid car.<\/p>\n To run a power\u2011hungry, 50\u2011metre\u2011class observatory at a remote, high\u2011altitude site without fossil fuels, the project is testing combinations of solar power, energy storage in batteries and metal hydride, as well as recovery of braking energy.<\/p>\n The researchers also plan to use near-zero carbon power to produce the steel and aluminium. The hope is that AtLAST2 will set a pattern for how large observatories can do ambitious science without jeopardising Europe\u2019s climate targets.<\/p>\n