Different ice types emit radiation that varies by five percent—invisible to conventional satellites.
High above the poles, two satellites no larger than shoeboxes are measuring something ancient and invisible: the heat Earth releases back into space. NASA's PREFIRE mission, launched in 2024, has begun capturing far-infrared radiation with a precision ten times greater than any instrument before it, revealing subtle differences in how ice, clouds, and snow breathe warmth into the cosmos. In a climate system where small imbalances carry large consequences, this quiet act of measurement may deepen our understanding of how the planet regulates itself — and how that regulation is changing.
- Climate models have long carried a blind spot: the far-infrared wavelengths that carry heat away from Earth's poles were largely invisible to conventional satellites, leaving a gap in our understanding of the planet's energy balance.
- Two CubeSats, each small enough to fit in a backpack, are now detecting radiation differences between ice types as subtle as five percent — distinctions that older instruments could not see and that carry real information about melting, accumulation, and cloud behavior.
- With their mission extended through September 2026, the satellites are expanding from polar observation to full global coverage, opening a new stream of data on moisture circulation, storm formation, and precipitation patterns worldwide.
- Scientists at JPL and the University of Wisconsin-Madison are preparing to feed this unprecedented data into weather and climate models, with the potential to sharpen storm forecasts and clarify how energy moves through the Earth system.
Somewhere over the Arctic, two shoebox-sized satellites are watching heat escape into space. NASA's PREFIRE mission — a pair of CubeSats launched from New Zealand in spring 2024 — has been measuring the far-infrared energy radiating from Earth's poles: the wavelengths that carry heat away from ice, snow, and clouds. With their mission now extended through September 2026, they are preparing to expand their gaze to cover the entire planet.
The physics behind PREFIRE is both elegant and consequential. Earth absorbs solar energy in the tropics and pushes it toward the poles through winds, ocean currents, and weather systems. At the poles, that energy radiates back into space as far-infrared light. The balance between what Earth absorbs and what it releases is one of the fundamental drivers of climate — and until now, it has been imperfectly measured.
What makes PREFIRE remarkable is its sensitivity. The mission's spectrometers, built by NASA's Jet Propulsion Laboratory, detect ten times more far-infrared wavelengths than any comparable instrument in orbit. This precision exposes details conventional satellites cannot see — including a roughly five-percent difference in how various ice types emit radiation. That small gap, invisible to older instruments, carries real signals about whether ice is melting, how clouds are shifting, and how the polar landscape is changing.
The two CubeSats travel in a staggered near-polar orbit, capturing two snapshots of the same location hours apart — enough to observe fast-moving phenomena like cloud cooling and surface warming. The science team initially focused on the poles, where the climate stakes are highest, but principal investigator Tristan L'Ecuyer sees the full opportunity: global data can reveal ice particle sizes in clouds everywhere, trace moisture circulation, and show how storms form and move across continents.
Built by Blue Canyon Technologies and processed by the University of Wisconsin-Madison, PREFIRE is a distributed collaboration with a singular aim — to see the invisible heat that shapes our world. As the mission expands to global coverage, it will feed a new stream of data into weather and climate models, giving forecasters sharper tools and giving scientists a clearer picture of how energy moves through the Earth system. Two small satellites, launched quietly from New Zealand, are beginning to reshape how we understand the heat our planet breathes away.
Somewhere over the Arctic, two shoebox-sized satellites are watching heat escape into space. They are NASA's PREFIRE mission—two CubeSats so small they fit in a backpack, yet so sensitive they can detect invisible radiation that other instruments miss entirely. Since their launch in spring 2024, these twin spacecraft have been measuring the far-infrared energy radiating from Earth's poles, the wavelengths of light that carry heat away from ice, snow, and clouds. Now, with their mission extended through September 2026, they are about to expand their gaze to cover the entire planet.
The physics behind PREFIRE is elegant and consequential. Earth absorbs enormous amounts of solar energy in the tropics, where the sun beats down directly. Winds, ocean currents, and weather systems push that heat toward the poles, which receive far less sunlight. At the poles, ice, snow, and clouds radiate some of that heat back into space as far-infrared radiation. The balance between the energy Earth absorbs and the energy it radiates away is one of the fundamental drivers of our climate. Get that balance wrong, and you misunderstand how the planet works.
What makes PREFIRE extraordinary is its sensitivity. The mission carries a pair of advanced spectrometers built by NASA's Jet Propulsion Laboratory that can detect ten times more far-infrared wavelengths than any comparable instrument flying today. This precision reveals details that conventional satellites cannot see. Take ice, for instance. Different types of ice—sea ice, glacial ice, snow—emit radiation at slightly different rates. The difference is small: about five percent. But it is real, and it matters. Conventional instruments operating at shorter wavelengths miss this distinction entirely. PREFIRE does not.
Brian Drouin, the mission's project scientist at JPL, understands what this means. Those five-percent differences between ice types are not academic curiosities. They are signals embedded in the radiation data that tell researchers something true about what is happening on the ground: whether ice is melting, whether snow is accumulating, how cloud cover is changing. These are the processes that reshape the polar landscape and, by extension, influence weather and climate across the entire globe.
The two CubeSats orbit in what is called an asynchronous near-polar orbit, traveling near the poles but hours apart from one another. This staggered timing is deliberate. It allows the mission to capture two separate snapshots of the same location over a short period, revealing phenomena that unfold quickly—like how clouds temporarily cool or warm the surface beneath them. The satellites have been collecting global data since launch, but the science team focused their initial analysis on the poles, where the physics is most dramatic and the climate stakes are highest.
Now comes the expansion. Tristan L'Ecuyer, the mission's principal investigator at the University of Wisconsin-Madison, sees the opportunity clearly. The satellites have the capacity to measure the entire world, not just the Arctic and Antarctic. By analyzing global data, researchers can determine the size of ice particles in clouds everywhere, understand how moisture circulates through the atmosphere, and trace where storms form and how rain and snow move across continents. This information can be fed directly into weather prediction models, making forecasts more accurate and improving our ability to anticipate severe weather.
The mission is a collaboration spanning multiple institutions and companies. JPL designed and manages the spectrometers. Blue Canyon Technologies built the CubeSats themselves. The University of Wisconsin-Madison processes the data. Rocket Lab USA launched both satellites from New Zealand in May and June 2024. It is a distributed effort, but the goal is singular: to see the invisible heat that shapes our world and, in seeing it, to understand climate and weather more deeply than we do today.
What happens next is straightforward in concept but profound in implication. As PREFIRE expands from polar focus to global coverage, it will feed a stream of unprecedented data into climate and weather models. Forecasters will have better information about moisture and clouds. Climate scientists will have a clearer picture of how energy moves through the Earth system. The five-percent difference between ice types, invisible to older instruments, will become part of the standard toolkit for understanding our changing planet. Two small satellites, launched quietly from New Zealand, are about to reshape how we see the heat that escapes from Earth.
Citas Notables
At these longer wavelengths, the amount of radiation going into space can differ from one type of ice to another by as much as 5 percent. Measurements that look at the same areas but with shorter wavelengths do not show this difference.— Brian Drouin, PREFIRE project scientist, NASA Jet Propulsion Laboratory
We have the capacity to collect data for the whole world, not just the poles. We'll be able to look at the size of ice particles in clouds that affect energy exchange between Earth and space and incorporate the data into weather prediction models to improve forecasts.— Tristan L'Ecuyer, PREFIRE principal investigator, University of Wisconsin-Madison
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that PREFIRE can see five percent more radiation from one type of ice than another? That sounds like a rounding error.
It would be, if ice were static. But ice is changing. When you're trying to understand whether a glacier is melting or a sea ice sheet is collapsing, that five percent is the difference between seeing the signal clearly and missing it entirely. Conventional satellites can't detect it at all.
So these CubeSats are basically giving us a new language for reading what's happening at the poles.
Exactly. And not just the poles anymore. The mission was designed for polar work because that's where the heat-radiation balance is most dramatic. But the satellites have been collecting global data all along. Now they're finally going to analyze it.
What changes when you expand from poles to the whole planet?
Everything becomes more complex and more useful. You can start to see how moisture moves from the tropics toward the poles, how that affects where storms form, how clouds influence local temperature. You can feed that into weather models and make better forecasts.
Better forecasts of what, specifically?
Storm severity, precipitation patterns, where rain will fall. The kind of information that matters to farmers, to emergency managers, to anyone planning for weather.
And this all comes from measuring invisible heat.
Yes. Far-infrared radiation is invisible to human eyes, but it carries information about what's happening on the surface. Ice, clouds, water vapor—they all have signatures in that wavelength. PREFIRE learned to read those signatures with unprecedented precision.