"Something Incredible Is Out There" --Scientists on Hunt for Signs of Extraterrestrial Intelligence Detect 15 New Cosmic Radio Bursts From Deep Space
As Carl Sagan was fond of saying: “Somewhere, something incredible is waiting to be known." Astronomers on the hunt for signs of extraterrestrial intelligence have detected 15 Fast Radio Bursts from a dwarf galaxy located three billion light-years away. These exotic pulses have confounded scientists since they were first discovered a decade ago by astronomers using the Parkes radio dish in Australia.
The 15 new FRBs were detected by scientists working on the Breakthrough Listen project—a 10-year mission to search the skies for signs of extraterrestrial intelligences (ETIs). Using the Green Bank Radio Telescope in West Virginia, the Breakthrough Listen team at UC Berkeley picked up the unusual signals on Monday August 28th. The larger astronomical community was quickly alerted.
“The conservative explanation for repeating FRBs is that they originate from a spinning neutron star which acts as a lighthouse [known as magnetars],” Avi Loeb, Chair of Harvard’s Astronomy Department, told Gizmodo. “Its beam of radiation is sweeping across the sky again and again because the star is subject to some external force that jolts it around. The circumstances must be different from a pulsar where the beam...is visible to the observer with an exact periodicity. FRBs appear to repeat in a non-periodic fashion. Moreover, FRBs are ten billion times brighter than pulsars, so the neutron star must be special, possibly very young (10-100 years old) and with a very strong magnetic field, producing much more powerful radiation than a typical pulsar.”
Loeb has speulated that FRBs might be artificially produced by an ETI’s antenna array for lightsail propulsion (similar to Breakthrough Starshot’s plan to send a lightsail to Proxima Centauri), and the repetitions are simply due to multiple firings of the launch system combined with the complicated motion of the beamer (on the source planet) relative to us. “But as Mark Twain said, ‘It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so’,” cautioned Loeb. “We should therefore wait for more data before jumping to conclusions.”
Or, as Carl Sagan said: "Exceptional claims required exceptional evidence."
“While it would be unwise to exclude the possibility that there are is other intelligent, technologically-capable, life in our universe, it is also unwise to immediately ascribe any new and poorly-understood astronomical phenomena to the work of alien life,” added Loeb.
FRBs from this source have never been seen at such high frequencies, explained Andrew Siemion, director of the Berkeley SETI Research Center and Breakthrough Listen, the highest of which reached 7 GHz. The Berkeley researchers say the high resolution data that they acquired will now enable scientists to measure the properties of FRBs at higher levels of precision than ever before. Over 400 terabytes of data was pulled in over a five hour period, as the researchers scanned the 4 to 8 GHz frequency band. The analysis by Siemion and Breakthrough Listen postdoctoral researcher Vishal Gajjar revealed the 15 new pulses.
“The extraordinary capabilities of the backend receiver, which is able to record several gigahertz of bandwidth at a time, split into billions of individual channels, enable a new view of the frequency spectrum of FRBs, and should shed additional light on the processes giving rise to FRB emission.” Gajjar said.
“We clearly have much more to learn about FRB 121102, and FRBs in general,” Siemion told the online technology site, Gizmodo. “While it would be unwise to exclude the possibility that there are is other intelligent, technologically-capable, life in our universe, it is also unwise to immediately ascribe any new and poorly-understood astronomical phenomena to the work of alien life.”
“As has happened with myriad other ‘strange’ phenomena (the CMB, pulsars themselves, gamma ray bursts, etc), we will probably find a natural explanation for FRB 121102 that, while not having to do with extraterrestrial intelligence, will never-the-less teach us something new about the universe,” he said.