Because of their transient nature—as well as the vast distances involved—scientists have struggled to study FRBs and determine their true origin and meaning. A new landmark discovery may localize an FRB with such exactitude that scientists can finally determine whether the phenomenon is natural or a product of sentient communication.
Scientists have been actively cataloging FRBs—which, incredibly, are believed to release approximately the same amount of energy in 1 millisecond as our sun does over the course of a century—since 2007. Since this time, they have identified 85 of the mysterious bursts, which are usually seen as “one-off” events but occasionally take the form of “repeaters” that duplicate the same signal in the same location.
The new one-off discovery of FRB 121102—the light from which has traveled for nearly four billion years to reach us—constitutes only the second time a fast radio burst has been tracked to its home galaxy. The team has pinpointed not only the home galaxy, but the specific region within that galaxy, which happens to be near the center—and likely close to—a supermassive black hole. Bannister’s team has ruled out the black hole as the source of the emission.
Lead author of the team that made the discovery, Keith Bannister, from Australia’s national science agency, stated:
“If we were to stand on the Moon and look down at the Earth with this precision, we would be able to tell not only which city the burst came from, but which postcode and even which city block. This is the big breakthrough the field has been waiting for since astronomers discovered fast radio bursts in 2007.”
Bannister and his Australian-led international team used the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope, which constitutes a network of 36 individual radio telescopes linked together. But in order for the scientists to glean such precise information about the FRB’s specific location, the team used a new technique that triangulated their findings with the slightly different arrival time data collected from two other telescopes—the European Southern Observatory’s Very Large Telescope in Chile measured its distance with the Keck telescope in Hawaii and the Gemini South telescope in Chile.
The team’s article on the discovery also paves the way for further research. In addition to potentially revolutionizing the way scientists study FRBs, the characteristics of this particular FRB in this particular galaxy will afford scientists a new way to study the non-luminous gas of vast intergalactic mediums, a poorly understood concept.
“The next step,” says co-author Ryan Shannon, “is to see if other one-off bursts are like FRB 180924 (originating in massive galaxies) or if they are more like the first repeater. I think they will be like 180924, and we will be able to open up a new window on the nearly invisible cosmic web.”
FRB research has accelerated in recent years. In 2017, astronomers embarked on the Breakthrough Listen Project, a $100 million endeavor that marshalled state of the art artificial intelligence (AI) to search for signs of life in the universe. The effort produced the discovery of 21 FRBs in the dwarf galaxy FRB 121102 in only an hour.
Most scientists take a moderately conservative approach to their speculation on the origin of FRBs, pointing at magnetars or magnetic oscillations of neutron stars as possible explanations. Other hypotheses include pulsar collapses and black hole collisions.
Other scientists say that FRBs could be the ideal way for advanced species to communicate or broadcast their existence over vast distances. Astrophysicists Avi Loeb and Manasvi Lingam have proposed the idea that FRBs may originate from alien solar sails, as such a propulsive source (widely viewed as a realistic form of interstellar travel) would require immense amounts of energy.