In a distant galaxy, some eight billion years ago, an enigmatic event set in motion a powerful surge of radio waves that journeyed across the cosmos. This extraordinary cosmic phenomenon, known as a fast radio burst (FRB), reached Earth on June 10 of the previous year. Despite its fleeting duration of less than a thousandth of a second, a radio telescope in Australia captured this elusive signal.
The nature and origins of fast radio bursts remain one of astronomy’s most compelling mysteries, with numerous theories attempting to explain their existence. Speculations range from the fantastical notion of alien signals to more plausible explanations involving dead stars called magnetars, known for their exceptional magnetic properties.
The recent FRB discovery has awed astronomers, and Ryan Shannon, an astrophysicist at Australia’s Swinburne University, described it as “mind-blowing.” The radio burst, detected by the ASKAP radio telescope in Western Australia, exceeded previous records, having traveled from a distance of approximately eight billion light-years, originating when the universe was less than half its current age.
This FRB packed a punch, releasing an energy equivalent to the sun’s output over 30 years in less than a millisecond. It is suggested that hundreds of thousands of such FRBs might occur in the sky each day, yet only around a thousand have been observed, with the source of merely 50 identified.
To trace the origin of the remarkable FRB, researchers turned to the Very Large Telescope in Chile. Their findings pointed to a galaxy exhibiting clumpy features, possibly due to merging with one or two other galaxies, giving rise to the potential magnetar. However, scientists admit that this remains a “best hunch” and that the actual cause of FRBs is yet to be conclusively determined.
Beyond solving the mysteries of FRBs, scientists aim to utilize them to explore the universe’s missing matter. Most of the universe consists of dark matter and energy, while only five percent comprises familiar, visible matter. However, more than half of this visible matter is unaccounted for. This missing matter is believed to be distributed in cosmic filaments connecting galaxies, forming the cosmic web, yet its diffuse nature makes it invisible to current telescopes.
Fast radio bursts provide a unique opportunity to study this elusive matter. These bursts carry the imprint of the gases they traverse, offering a means to measure this matter. To calculate the total weight of the universe, hundreds more FRBs need to be observed, with the prospect of advanced radio telescopes increasing this possibility.
As future radio telescopes come online, it is anticipated that they will detect tens of thousands of FRBs, enabling scientists to unravel the cosmic mysteries across different epochs and ascertain the universe’s weight.
Fast radio bursts have emerged as invaluable cosmic messengers in the quest to unlock the secrets of the cosmos.