Fast radio bursts (FRBs), mysterious high-energy astrophysical phenoma that have defied explanation, have been blamed on everything from aliens to microwave ovens. They are incredibly strong signals that have puzzling mathematical regularity, and scientists believe they are coming from deep space.
Now, a recently constructed telescope in Canada has detected 13 FRBs from deep space, including one that flashed repeatedly six times. The "repeater" is only the second known one of its kind to have been discovered.
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope in British Columbia made these observations from July to August 2018 during its "pre-commissioning" phase before it was even fully operational.
"CHIME reconstructs the image of the overhead sky by processing the radio signals recorded by thousands of antennas with a large signal-processing system," Kendrick Smith, of the Perimeter Institute for Theoretical Physics in Ontario, told Space.com. "CHIME's signal-processing system is the largest of any telescope on Earth, allowing it to search huge regions of the sky simultaneously."
The repeater, called FRB 180814.J0422+73, is about 1.5 billion light-years away from Earth. While that distance seems hard to fathom, it's actually two times closer than the first-discovered repeater, FRB 121102, which has sent out dozens of signals over the past several years.
Now with these new discoveries from CHIME, the number of FRBs recorded has increased by 20 percent. Astronomers also believe now that FRBs may be more common than previously thought but that technology hasn't caught up yet to detect all of them.
CHIME is groundbreaking also because its range is from 400 to 800 megahertz MHz, whereas previously discovered FRBs had radio frequencies around 1,400 MHz.
"[FRB] Sources can produce low-frequency radio waves, and those low-frequency waves can escape their environment and are not too scattered to be detected by the time they reach the Earth," CHIME team member Tom Landecker, from the National Research Council of Canada, told Space.com. "That tells us something about the environments and the sources...We haven’t solved the problem, but it’s several more pieces in the puzzle."
While CHIME may be leading the way in finding low-frequency FRBs, another radio telescope picked up on a unique FRB a few years ago that shed light on its mysterious origin and helped lay the groundwork for further analysis of matter in our universe.
How a faint glow from a FRB sparks a theory
While scientists still haven't exactly pinpointed whether or not FRBs all come from the same type of source or are vastly different in origin, scientists in Australia believe they discovered one source back in 2015.
Or at least, they confirmed the source of one of the fast radio bursts: a galaxy roughly 6 billion light-years away in the Canis Major constellation, reported Science News. That's a long way away, proving once and for all that these perplexing radio signals are not coming from within our own galaxy.
The bursts have been difficult to pinpoint, in part because they last only a few milliseconds but also because only several dozen of them have ever been detected. But a burst captured by the Parkes radio telescope in Australia in April of 2015, was followed by a faint radio glow that slowly faded over the course of six days. This additional glow offered enough information for scientists to trace the burst back to its origin, a distant elliptical galaxy.
Scientists suspected that the burst might have been generated from a merging pair of neutron stars, though this is just one hypothesis. It's also possible that fast radio bursts come in several different varieties and have different sources. That this particular burst's galaxy of origin has been pinpointed does not mean that the origin of the phenomenon itself has been solved. There's much still to learn about these peculiar signals.
Interestingly, the search for this burst's source might also have solved another riddle of the universe: the so-called "missing matter" problem. There should be much more matter in our universe than scientists have been able to detect so far, at least according to current models of the universe. This fast radio burst showed a lot of "wear and tear," however — and that's evidence that it must have bumped into lots of matter during its journey through the space between galaxies.
This could be the missing matter that scientists have been looking for, invisible ions hidden in the darkness of intergalactic space.
These are all exciting finds, proof that there's a lot of good science that can come from studying these mystifying signals, whether they lead to aliens, merging neutron stars or something else entirely.
Editor's note: This article has been updated since it was originally published in February 2016.