KALEDEN, British Columbia - Scientists recently discovered several new repeating radio signals making their way to Earth from different locations in the universe, and no one knows yet what is causing them.
Eight new repeating fast radio burst (FRB) sources have been discovered using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope, and the findings were published in a report on Arxiv earlier this month.
Scientists believe one of these repeating signals could be coming from relatively nearby, perhaps just beyond the Milky Way, but their report cautions that more research needs to be done to be certain.
FRBs are very short bursts of radio waves — they only last for a few milliseconds — and they originate from beyond the Milky Way galaxy.
Nobody knows what causes these FRBs and where exactly they come from, but because the blasts are so intense, scientists believe they are likely coming from some sort of extreme cosmic event. In terms of what those events could be, the possibilities are somewhat endless, ranging from a star being sucked into a black hole to aliens attempting to contact us from some distant point in space.
Single FRBs are hard to study and locate because they are so brief, which is why finding repeating FRBs is a pretty big deal. The new discovery of eight of them is massive because only two had been confirmed prior.
“The repetition tells you something about the cause of these radio flashes. Obviously, you can’t expect that colliding black holes or neutron stars are going to return to their corners and collide again a few days later,” says Seth Shostak, a senior astronomer at the SETI Institute. “Whatever is responsible for this series of bursts has to be an ongoing phenomenon.”
The more repeating FRBs that scientists find, the easier it is to learn about these phenomena.The discovery of their existence was very recent — the first repeating FRB was discovered by the Arecibo Observatory in Puerto Rico in November 2012. Called FRB 121102, this particular repeating FRB is coming from a small dwarf galaxy many dozens of times smaller than the Milky Way that is approximately three billion light-years away.
“FRB 121102 is more than merely far, far away and long, long ago,” Shostak explains. “It’s more powerful than nearly anything you can name. Indeed, if you assume that energy from the burst is radiated in all directions, then in an eyeblink this object let loose about as much energy as the Sun pumps out in a year. Or if that doesn’t impress you, it’s enough energy to run humanity (at its present, prodigious burn rate) for 10 trillion years.”
All this new data from CHIME’s most recent discovery has the potential to teach scientists more about FRBs, like the fact that one of the new repeating FRBs is coming from a source with a much lower Faraday Rotation Measure than FRB 121102. This suggests that not all repeating FRBs share the same environmental properties of FRB 121102.
The new repeating FRBs were determined to have larger burst widths than non-repeating FRBs detected by CHIME, and this suggests that repeating and non-repeating sources have different mechanisms for emitting these signals.
So, what’s the likelihood that these signals are from aliens trying to communicate with us?
Shostak says you can “safely bet” that aliens aren’t the cause of it all due to the fact that FRBs are seen all over the sky and are coming from galaxies that are typically separated by billions of light-years.
“So how could aliens organize so much of the universe to engage in broadcasting the same sort of signal? There’s hardly been enough time since the Big Bang to coordinate such widespread teamwork, even if you can think of a reason for it,” said Shostak.
With the amount of FRBs that have been discovered in recent years, researchers can safely assume that there are likely many FRBs occurring each day. Scientists will continue working to identify and locate as many as possible until these bewildering cosmic phenomena are explained — aliens or not.
This story was reported from Los Angeles.