Questions that once seemed impossible to answer are now within reach.
For two decades, astronomers studying the cosmos were working half-blind, unable to see the southern sky and constrained by the same limited dataset. Now, an international team led by CSIRO has released SPICE-RACS — a magnetic map of the Universe five times larger than all previous efforts combined — by measuring how light twists as it passes through magnetic fields across billions of light-years. The map, drawn from nearly four million galaxies observed by the ASKAP telescope in Western Australia, opens a new chapter in humanity's effort to understand the invisible forces that have shaped galaxies, matter, and cosmic evolution since the beginning of time.
- For twenty years, the study of cosmic magnetism was frozen in place — the same limited data, the same blind spots, the same unanswered questions about when and how magnetic fields first emerged in the Universe.
- The release of SPICE-RACS shatters that stagnation: a single map, five times larger than everything that came before, built by measuring the subtle twist of light as it travels billions of light-years through magnetic fields.
- The ASKAP telescope's wide-field vision, unique dish rotation system, and extraordinary computational muscle made it possible to process nearly four million galaxies simultaneously — a feat unimaginable just a few years ago.
- Scientists can now investigate how magnetic fields shape galaxy formation, how matter moves through intergalactic space, and how the Milky Way interacts with its neighbors — questions that once seemed permanently out of reach.
- CSIRO has made all the data freely available, and research teams worldwide are already producing new results — a deliberate acceleration of discovery that will only build momentum.
- The next transformation is already on the horizon: SKA telescopes under construction in Australia and South Africa will map the cosmic web in still finer detail, potentially answering the deepest questions about the origin of magnetic fields in the Universe.
For two decades, astronomers studying the Universe's magnetic fields worked with the same constrained dataset, unable to observe the southern sky at all. That era has now ended. An international team led by CSIRO and the SKA Observatory has released SPICE-RACS — a magnetic map of the Universe five times larger than all previous efforts combined — marking what researchers describe as the beginning of an entirely new chapter in cosmic science.
The map was built from light itself. As photons travel billions of light-years through space, they twist when passing through magnetic fields. By measuring exactly how much that twist occurs, Dr. Alec Thomson and his team could locate magnetic fields and gauge their strength across the cosmos. The ASKAP radio telescope, situated on Wajarri Yamaji Country in Western Australia, detected nearly four million galaxies and collected rotation measurements from each — a feat made possible by ASKAP's wide field of view, its unique dish rotation system, and the computational power to process vast quantities of diverse data.
The implications reach across fundamental questions in astronomy. Magnetic fields influence how galaxies grow, how matter moves through space, and how the Universe has evolved over billions of years. Questions once considered unanswerable — when did magnetic fields first appear? How do they shape interactions between the Milky Way and the Magellanic Clouds? — are now within reach. Professor Naomi McClure-Griffiths, the SKA Observatory's Chief Scientist, called it a huge leap forward.
CSIRO has made the maps freely available through its data portal, and research teams are already using them to produce new results. The collaboration behind SPICE-RACS plans to release even better maps using ASKAP in the coming years. But the deeper transformation arrives later this decade, when the new SKA telescopes in Australia and South Africa begin operations — instruments that will chart the cosmic web in finer detail than anything now possible, and may finally unlock the oldest mysteries of how magnetic fields were born across the history of the Universe.
For two decades, astronomers studying the Universe's magnetic fields have been working with the same limited dataset, unable to see the southern sky at all. That constraint has just ended. An international team led by researchers at CSIRO and the SKA Observatory has released SPICE-RACS, a magnetic map of the Universe five times larger than all previous efforts combined—a map so detailed it represents the beginning of an entirely new chapter in how scientists understand the invisible forces that shape galaxies.
The map emerged from an unlikely source: light itself. As photons travel billions of light-years through space, they twist when passing through magnetic fields. By measuring exactly how much that light has twisted, Dr. Alec Thomson and his team could pinpoint where magnetic fields exist and gauge their strength. The ASKAP radio telescope, located at the CSIRO Murchison Radio-astronomy Observatory on Wajarri Yamaji Country in Western Australia, detected nearly four million galaxies and collected rotation measurements from each one. The team then reprocessed the original data to construct the full picture—a feat that would have been impossible even a few years ago.
What makes this possible now is a convergence of technological advances. ASKAP's wide field of view allows it to scan enormous swaths of sky simultaneously. Its unique dish rotation system and the sheer computational power to process vast quantities of diverse data have unlocked what was previously out of reach. The telescope itself is a precursor to the SKA telescopes currently under construction in Australia and South Africa—instruments that will eventually enable even finer cosmic mapping.
The implications ripple across fundamental questions in astronomy. Magnetic fields influence how galaxies grow, how matter moves through space, and how the Universe has evolved over billions of years. With this new map, scientists can finally investigate fine details of material between nearby stars and study distant galaxies at scale. Professor Naomi McClure-Griffiths, the SKA Observatory's Chief Scientist and a leader in magnetism research, described it as a huge leap forward. Questions that once seemed impossible to answer—when did magnetic fields first appear in the Universe? How do they affect interactions between galaxies like the Milky Way and the Magellanic Clouds?—are now within reach.
The data itself is not locked away. CSIRO has made the maps freely available through its data portal at data.csiro.au, accessible to scientists locally and around the world. This openness reflects a deliberate choice: by sharing the raw materials of discovery, the agency is accelerating the pace at which the scientific community can build new insights. Research teams are already using the data to produce novel results, and that momentum will only grow.
The work of the Polarisation Sky Survey of the Universe's Magnetism collaboration—the international team behind this effort—is far from finished. They plan to produce even better maps over the coming years using ASKAP. But the real transformation arrives later this decade, when the new SKA telescopes begin early operations. Those instruments will chart the cosmic web in finer detail than anything now possible, potentially unlocking the deepest mysteries of how magnetic fields originated and evolved across the history of the Universe.
Citas Notables
For the first time, we can investigate fine details of the material between nearby stars, and study a huge number of distant galaxies.— Dr. Alec Thomson, commissioning scientist with the SKA Observatory
For the past 20 years we have been working with essentially the same data set, which didn't even cover the southern sky. Now, we can finally answer some big questions with a much better picture of the Universe's magnetic structures.— Professor Naomi McClure-Griffiths, SKA Observatory Chief Scientist
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that light twists through magnetic fields? What are we actually learning?
The twist tells us where the magnetic fields are and how strong they are. For twenty years, we've been essentially blind to the southern sky's magnetism. Now we can see it. That changes everything about how we understand galaxy formation.
Four million galaxies is a staggering number. How do you even process that much information?
ASKAP was designed to do exactly this—it can see huge areas of sky at once. But the real breakthrough is computational. We have the ability now to reprocess all that raw data and extract the full magnetic picture. Five years ago, we couldn't have done this.
You mentioned questions that seemed impossible to answer. Like when magnetic fields first appeared. Why is that so hard?
Because you need to see far enough back in time and across enough of the Universe to trace the pattern. You need density and scale. This map gives us both for the first time.
What happens next? Is this the end of the story or the beginning?
The beginning. ASKAP will keep producing better maps. But the real transformation comes when the SKA telescopes start operating later this decade. Those will see details we can't even imagine yet.
Why did CSIRO choose to make all this data public?
Because science moves faster when everyone can see the same evidence. Teams around the world are already using it to answer their own questions. That's how understanding accelerates.