We're seeing only the tip of the iceberg right now.
For as long as humans have studied the night sky, roughly half of the universe's light has remained invisible to us, swallowed by interstellar dust before it could reach our instruments. Now, a consortium of nine nations is designing AtLAST — a 50-meter submillimeter telescope to be built in Chile's Atacama Desert — to pierce that cosmic veil and reveal galaxies, stellar nurseries, and molecular origins that have never been observed. The project is not merely a technological leap but a philosophical one: a recognition that the universe we thought we knew is only half the story, and that seeing it whole requires both scientific ambition and the humility to collaborate across borders.
- Half of all light produced by galaxies never reaches Earth-based telescopes, meaning our entire picture of the cosmos is built on an incomplete foundation.
- Current instruments like ALMA, though powerful, see only a sliver of the sky at a time — a field of view thousands of times smaller than the Moon's apparent surface — leaving vast cosmic regions unmapped.
- AtLAST's 50-meter mirror will capture sky areas 16 times the Moon's apparent size in a single exposure, potentially identifying 50 million galaxies in just 1,000 hours of observation.
- Nine countries, including the U.S., Japan, and several European nations, have set aside competing national telescope projects to fund and design this shared instrument through 2028.
- The telescope will run entirely on renewable energy — solar, battery, and metal hydride storage — marking a significant shift in how large-scale scientific infrastructure is built and powered.
- With a planned 50-year operational life, AtLAST is positioned to detect transient cosmic events, trace the chemical origins of life, and reveal structures that current science cannot yet imagine.
For centuries, humans have marveled at the night sky without realizing that roughly half of all the light the universe produces never reaches our eyes. Dust clouds scattered across space intercept it, absorbing the radiation before it can travel to Earth. Now an international team is building a machine designed to see what has always been hidden.
The Atacama Large Aperture Submillimeter Telescope — AtLAST — will be stationed in Chile's Atacama Desert at an altitude above 5,000 meters, where the dry atmosphere allows submillimeter radiation to pass through. Its primary mirror, 50 meters in diameter, will function like a wide-angle camera, mapping regions of sky up to 16 times the apparent size of the Moon in a single exposure. By contrast, the existing ALMA array nearby can see an area thousands of times smaller than the Moon's face in one observation.
Astrophysicist Claudia Cicone of the University of Oslo describes the current state of astronomy as seeing only the tip of an iceberg. The missing half of galactic light contains crucial information about star formation, gas distribution, and how galaxies evolve over cosmic time. AtLAST could identify as many as 50 million galaxies in 1,000 hours of observation — a number that would transform our census of the cosmos.
Nine countries are involved in the project: the United States, Canada, Japan, Thailand, Taiwan, New Zealand, South Africa, Chile, and several European nations. Japan had once planned its own large submillimeter telescope but chose to join this collective effort instead, recognizing that shared resources would yield better science than competing national projects. The European Union is funding the design phase through 2028.
What distinguishes AtLAST beyond its scale is its commitment to sustainability. The facility will run entirely on renewable energy through a hybrid system of solar panels, battery storage, and metal hydride technology — even capturing kinetic energy from the telescope's own movements. For a project of this magnitude, such environmental ambition marks a genuine shift in how major scientific infrastructure is conceived.
Over its planned 50-year lifespan, AtLAST will study solar flares, search for the molecular building blocks of life in stellar nurseries, and detect transient cosmic events that current instruments cannot even hint at. More than a bigger telescope, it represents a new model for how nations choose to explore the unknown — not in competition, but together, reaching toward a universe that has always been there, waiting to be seen whole.
For centuries, humans have gazed upward at the night sky and marveled at what they could see. What most people don't realize is that the hazy glow of the Milky Way conceals something far larger—roughly half of all the light the universe produces never reaches our eyes. Dust clouds scattered across space intercept it, swallowing the radiation before it can travel the vast distances to Earth. Now an international team of astronomers is building a machine to see what has always been hidden. The Atacama Large Aperture Submillimeter Telescope, or AtLAST, is designed to pierce through that cosmic veil and detect the radiation that conventional optical telescopes cannot capture. When it becomes operational in the Atacama Desert of northern Chile, it will fundamentally change what we know about how galaxies form, how stars are born, and what the universe actually contains.
The problem is straightforward but profound. Existing telescopes—even the most sophisticated ones—can only observe a fraction of reality. The Atacama Large Millimeter/submillimeter Array, or ALMA, which already operates in the same desert, represents the cutting edge of current technology. Yet ALMA's field of view is remarkably narrow. In a single observation, it can see an area thousands of times smaller than the surface of the Moon as it appears in Earth's sky. AtLAST will work differently. With a primary mirror 50 meters in diameter—the largest of its kind—it will function like a wide-angle camera, capable of mapping regions of the sky up to 16 times the apparent size of the Moon in a single exposure. This leap in capability will allow astronomers to see not just isolated objects but entire cosmic neighborhoods at once.
The science driving the project is ambitious. Claudia Cicone, an astrophysicist at the University of Oslo and one of the project's lead researchers, describes the current state of astronomy as seeing only the tip of an iceberg. About half of all light produced by galaxies is blocked by interstellar dust before it can reach Earth-based instruments. That missing half contains crucial information about where gas and dust exist in the universe, how quickly stars form, and how galaxies evolve over cosmic time. With AtLAST, scientists estimate they could identify as many as 50 million galaxies in just 1,000 hours of observation—a staggering number that would transform our census of the cosmos and allow researchers to distinguish individual sources in regions so densely packed that current instruments see only a blur.
The project itself is a product of international collaboration. Nine countries are involved: the United States, Canada, Japan, Thailand, Taiwan, New Zealand, South Africa, Chile, and several European nations. The European Union is funding the design phase, which runs through 2028. Japan's participation is particularly significant. The country had once planned to build its own large submillimeter telescope, called the LST, but chose instead to join this global effort. Cicone notes that the decision reflected a recognition that pooling resources and expertise would yield better science than competing national projects.
The Atacama Desert location was chosen deliberately. At an altitude above 5,000 meters, with an exceptionally dry atmosphere, the site offers ideal conditions for observing submillimeter radiation—the wavelengths that can penetrate dust clouds. ALMA already operates nearby, so infrastructure and expertise are in place. The telescope itself will be a marvel of engineering: a structure of steel and aluminum with a secondary mirror 12 meters across, larger than most existing telescopes in their entirety.
What sets AtLAST apart from previous megaprojects is its commitment to sustainability. The entire facility will run on renewable energy. The design incorporates a hybrid system combining solar panels, battery storage, and metal hydride energy storage—a technology that works similarly to the regenerative braking systems in hybrid cars. The kinetic energy generated by the telescope's movements will be captured and reused. Even the manufacturing of components will prioritize low-carbon or zero-carbon production methods. For a project of this scale, such environmental considerations represent a significant shift in how major scientific infrastructure is conceived.
The science questions AtLAST will address range from the immediate to the fundamental. Researchers plan to study the solar atmosphere and the variability of solar flares with unprecedented detail. They will examine complex molecules in molecular clouds—the stellar nurseries where stars and planets form—and search for the chemical building blocks that may have led to life. The telescope's sensitivity to transient events—brief, unexpected phenomena in the submillimeter spectrum—means that discoveries may come from places no one anticipated. Over its planned 50-year operational life, AtLAST could reveal cosmic events and structures that current instruments cannot even hint at.
The project represents more than just a bigger, better telescope. It embodies a shift in how international science operates. Rather than nations competing to build the largest instrument, they are choosing to collaborate on something none could build alone. When AtLAST begins observations, it will be looking at a universe that has always been there, waiting to be seen. For the first time, we will have the tools to see it whole.
Notable Quotes
We are missing the regions of space that are most covered in dust.— Claudia Cicone, astrophysicist and project lead
ALMA can see an area thousands of times smaller than the surface of the Moon in each observation.— Tony Mroczkowski, Institute of Space Sciences, Spain
The Hearth Conversation Another angle on the story
Why does dust matter so much? Can't we just look around it?
Dust doesn't just obscure—it absorbs. When light from a distant galaxy passes through a cloud of interstellar dust, the dust particles capture that radiation and convert it to heat. It's gone. But those same dust clouds emit radiation at submillimeter wavelengths, which AtLAST can detect. So we're not looking around the dust; we're reading the light the dust itself is giving off.
And that tells us what, exactly?
It tells us where stars are forming, how fast galaxies are evolving, how much gas and dust exists in different regions of space. Right now we're missing half the story. We see the bright, dust-free galaxies clearly, but the dusty ones—often the most active, most interesting ones—are invisible to us.
Fifty million galaxies in a thousand hours sounds enormous. What do you do with that much data?
You start asking questions you couldn't ask before. With ALMA, you can study individual galaxies in exquisite detail, but you can only look at a handful at a time. With AtLAST, you can map entire regions and see patterns—how galaxies cluster, how they interact, how their properties change across space and time.
Why did Japan decide to join rather than build their own telescope?
Because they realized the science would be better. A single nation's telescope, no matter how large, has limits. But a global instrument with contributions from nine countries means more expertise, more funding, more observing time shared among more scientists. It's a recognition that some problems are too big for one country to solve alone.
The renewable energy aspect seems unusual for a major observatory.
It is. Most large telescopes are built with whatever power infrastructure exists. But AtLAST is being designed from the ground up to run on solar, batteries, and regenerative systems. It's partly about environmental responsibility, but it's also practical—the Atacama is sunny and remote, so renewable energy makes sense. And it sets a precedent for how future megaprojects should be built.
What's the biggest discovery you think it could make?
That's the honest answer: we don't know. That's what makes it exciting. We know it will answer questions about star formation and galaxy evolution. But transient events—brief phenomena we can't predict—might reveal something entirely unexpected. Over fifty years, that's a lot of opportunity for surprise.