In a spectacular cosmic revelation, an international group of astronomers recorded a flash of radio waves coming from a galaxy so distant that its signals took eight billion years to reach Earth. This “fast radio burst” or FRB, labeled FRB 20220610A, is not only the most distant but also among the most powerful ever observed, unleashing energy equivalent to what our Sun produces over three decades—all in less than a millisecond.
This monumental discovery was first identified last June by the Australian ASKAP radio telescope and later analyzed using the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile.
“Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” says Stuart Ryder from Macquarie University in Australia, and co-lead author of the study, in a statement. The source, he explains, is “older and further away than any other FRB source found to date and likely within a small group of merging galaxies.”
But why is such a distant flicker of radio waves significant? Beyond being a cosmic spectacle, FRBs offer a groundbreaking way to solve the universal conundrum of the missing matter. Essentially, while scientists can estimate the mass of the universe, over half of the “normal matter”—the atoms constituting everything we see, including ourselves—is inexplicably absent.
“If we count up the amount of normal matter in the universe… we find that more than half of what should be there today is missing,” explains Ryan Shannon, a professor at Swinburne University of Technology in Australia and study co-leader. The team hypothesizes this “ghost” matter might be trapped in spaces between galaxies, eluding detection because of its extreme temperature and diffuse state.
Remarkably, FRBs could be the cosmic detectives we need. “Fast radio bursts sense this ionized material. Even in space that is nearly perfectly empty they can ‘see’ all the electrons, and that allows us to measure how much stuff is between the galaxies,” Shannon reveals.
The importance of uncovering distant FRBs was emphasized by the late Australian astronomer Jean-Pierre Macquart. He asserted that the further an FRB is, the more it exposes the elusive gas between galaxies—a principle now known as the Macquart relation. “Our measurements confirm the Macquart relation holds out to beyond half the known universe,” says Ryder.
Despite their proven significance in cosmic measurement, the actual origins of these intense energy bursts remain a mystery. However, Shannon points out, “the paper confirms that fast radio bursts are common events in the cosmos” and crucially, they are a resource for detecting intergalactic matter and comprehending the universe’s structure.
This discovery pushes the boundaries of our current astronomical capabilities, but it won’t for long. With the impending completion of advanced facilities like the Square Kilometer Array Observatory’s radio telescopes in South Africa and Australia, and ESO’s Extremely Large Telescope in Chile, the cosmic horizon will expand further. These instruments, capable of detecting even older and more distant cosmic phenomena, promise to unlock more secrets of the universe, perhaps even identifying the enigmatic sources of FRBs.
The research paper is published in the journal Science.