A groundbreaking map of cosmic magnetic fields has been created using the Australian Square Kilometre Array Pathfinder (ASKAP), the most powerful radio telescope in the world. Magnetic fields are essential to the structure of the universe, influencing the movement of particles that form planets, stars, and galaxies. While their origin is still a mystery, magnetic fields are everywhere, from Earth's protective shield that guides compass needles and migratory birds to the intense fields surrounding black holes and neutron stars. The study, published in the Publications of the Astronomical Society of Australia, used ASKAP to produce the largest and most detailed map of cosmic magnetic fields ever made. Radio telescopes detect radio waves from distant galaxies, revealing structures in space that are otherwise invisible to optical telescopes. These magnetic fields vary dramatically across the universe, ranging from fields billions of times stronger than Earth's around dense objects like black holes to fields a million times weaker in the space between stars. Astronomers detect these magnetic fields by observing how light becomes polarized as it travels through them. Polarization refers to the direction in which light waves oscillate, and when light passes through a magnetic field, this direction changes. By studying this effect, especially in the radio spectrum, scientists can map the magnetic fields of distant galaxies. Australia has been a leader in radio astronomy since the 1960s, when researchers first detected the twisting of light polarization caused by magnetic fields beyond Earth. However, the last major cosmic magnetic field map was made in 2009, and no comprehensive update has followed, leaving many questions about the intensity and structure of magnetic fields in different parts of the universe unanswered. The Square Kilometre Array (SKA), a new generation of radio telescopes under construction in South Africa and Australia, aims to change that. The new map, called SPICE-RACS, was created using data from the Rapid ASKAP Continuum Surveys (RACS), which identified nearly four million galaxies, about two million of which had never been observed before. Researchers analyzed 350,000 of these galaxies to detect polarization changes caused by magnetic fields. This dataset is nearly ten times larger than the previous largest dataset and five times larger than all earlier observations combined. The map uses red and blue colors to show the direction of magnetic fields—red for fields pointing toward the observer and blue for those pointing away. Most of the complex patterns seen on the map originate from the Milky Way, but the map also reveals details from much farther in the universe. The data are now available online for scientists worldwide, and future efforts aim to combine all RACS data to create an even more comprehensive map. The POSSUM project, which aims to map the universe’s magnetic fields in detail, is expected to complete its observations by 2030, offering new insights into the history and evolution of the cosmos.