Radio telescope and starlight merge to reveal Universe's invisible magnetic fields

On a moonless night in the Australian outback, about 500 miles north of Perth, astrophotographer Alex Cherney stood alone among the massive dishes of CSIRO's ASKAP radio telescope. The Milky Way hung overhead so bright he could see his own shadow cast by starlight alone. For most nights, photography is forbidden here—the electronic sensitivity of the instruments means any stray light or electromagnetic noise will corrupt the observations. But tonight the telescope was silent, and Cherney had been given something rare: permission to work.

He spent the entire night waiting for the right moment, from sunset until just before dawn. His camera, specially modified to capture wavelengths invisible to the human eye, would record not just what we see but what lies hidden in the ultraviolet and infrared spectrum—the deep red glow of hydrogen clouds at the galaxy's heart. When the Milky Way finally tilted into the perfect position, he knew. He took ten photographs in quick succession, each exposed for thirty seconds, long enough to gather light but short enough that the stars wouldn't blur into streaks. Later, in his studio, he would stitch these ten images into a single panoramic photograph that would become the foundation for something larger than astronomy alone.

While Cherney was composing his image, Dr. Alec Thomson and an international team of researchers were using the same sky in an entirely different way. The ASKAP telescope had collected data on four million distant galaxies. From that vast dataset, Thomson's team selected 350,000 galaxies and used them to map something no one had ever mapped in such detail: the magnetic fields of the universe. They accomplished this by measuring how light from distant galaxies twists and bends as it travels through the magnetic fields between us and them—a technique called polarimetry. The result was SPICE-RACS, a magnetic map five times larger than all previous attempts combined. For the first time, astronomers could see the fine structure of magnetic material between nearby stars and study the magnetic signatures of galaxies across the cosmos.

The data itself exists as numbers and coordinates, but Thomson's team also generated a visual representation: red showing magnetic fields pointing toward Earth, blue showing fields pointing away. It was scientifically precise but abstract—a catalogue of the invisible rendered in color. This is where the collaboration deepened. Digital artist Sam Moorfield, who specializes in space visualization, took Cherney's panoramic photograph of the Milky Way and the ASKAP dishes and began the delicate work of overlaying Thomson's magnetic map onto it. The process demanded absolute accuracy. Moorfield had to align the galactic coordinates—the positions of the Magellanic Clouds, the plane of the Milky Way itself—with the telescope's physical location. He added subtle artistic touches: a glow at the horizon, detailed etching around the telescope's dishes, careful placement of the magnetic overlay so it sat correctly behind trees and instruments. "Accuracy is everything," Moorfield said. "There's no such thing as 'near enough is good enough' when combining these images."

What emerged was something neither science nor art alone could have produced: a photograph of the night sky as we experience it, overlaid with a map of forces we cannot see. The invisible made visible. The magnetic fields that shape galaxies, that guide the movement of energy through the cosmos, suddenly appeared as patterns of red and blue superimposed on the stars themselves. Cherney, seeing his photograph transformed into part of a scientific visualization, felt humbled. Thomson's team had opened their data freely to the world—any researcher anywhere could now access the most detailed magnetic map of the universe ever created and use it to understand how galaxies form, evolve, and move. A team of a photographer, a scientist, and an artist had connected two worlds, revealing what had always been there but remained invisible until someone found the right way to show it.