Australia launches SABRE South to hunt for dark matter
After more than a decade of planning, Australia is preparing to advance one of the most elusive quests in modern science: detecting dark matter. The SABRE South experiment will be housed deep underground in the Stawell Gold Mine, nestled in regional Victoria, where the rock overhead and additional shielding by steel and plastics are designed to minimize interference from cosmic rays. The project aims to begin data collection next year, bringing Australia into a global race to unravel one of the universe’s greatest mysteries.
The hunt for dark matter
Dark matter is a form of matter that does not emit, absorb, or reflect light, making it invisible to telescopes. Yet its presence is inferred from gravitational effects on galaxies and galaxy clusters. The idea first gained traction in the 1930s and gained renewed momentum in the late 20th century as astronomers and physicists sought to explain discrepancies in celestial motions. In 1998, the DAMA experiment, buried under Italy’s Gran Sasso mountain, claimed to have detected signals compatible with dark matter particles, specifically a class of particles called WIMPs (weakly interacting massive particles).
Since then, the scientific community has pursued independent verification across different detectors and hemispheres. SABRE South is designed to contribute to this verification effort by attempting to reproduce or challenge the DAMA observations from the Southern Hemisphere—an essential cross-check for any claimed dark matter signal.
How SABRE South detects dark matter
The core of SABRE South comprises several sodium-iodide crystals arranged to act as a sensitive detector for particles that could be dark matter. The working hypothesis is that a passing WIMP could collide with a nucleus in the crystal, producing tiny flash of light that, with precise instrumentation, researchers can record and analyze. The Seduction of such faint signals requires stringent shielding: the facility sits beneath nearly a kilometer of rock and is reinforced with steel and plastic layers to suppress cosmic ray interference and other environmental background noise.
Leading the project is Professor Phillip Urquijo, an experimental particle physicist who notes that three major research teams are racing to replicate the DAMA findings—teams in South Korea, Spain, and Italy. The SABRE South team welcomes this international competition, arguing that multiple, independent experiments are the best path to reliable results. Importantly, SABRE South’s geographic location provides a unique southern-hemisphere perspective, which could help validate any potential signals by offering a different set of environmental conditions and seasonal variations to study.
Why the southern hemisphere matters
If dark matter interacts with ordinary matter as hypothesized, detectors in different parts of the world should observe similar signals, modulo local environmental factors. By operating in the Southern Hemisphere, SABRE South helps astronomers check for seasonal or equipment-related biases that might mimic a dark matter signal. As Elisabetta Barberio, director of the ARC Centre of Excellence for Dark Matter Particle Physics, told ABC News, the pursuit is part of a broader effort to understand what composes the majority of the cosmos—an objective that dark energy and dark matter jointly dominate.
A measured path forward
Urquijo emphasizes the cautious pace of discovery. “We’re looking for the seasonal effects, so if we just saw it one year, we might say that’s a fluke,” he said. “You need five years to see it—you need to make sure that it’s not a mistake.” The SABRE South experiment is designed to provide robust, long-term data that can stand up to rigorous scrutiny and cross-examination with results from other detectors around the world.
What success could mean
Confirming a dark matter signal would not only cement a long-sought discovery but also reshape our understanding of the universe’s most abundant yet mysterious substance. If SABRE South and its international counterparts corroborate DAMA-like signals, physicists might gain crucial insight into the properties of WIMPs and how dark matter interacts with normal matter. In the meantime, the project represents a substantial milestone for Australia’s role in high-energy physics and the global hunt for the universe’s hidden mass.
