From the flats of rural Australia, to the hills of West Virginia, some of the world’s
largest telescopes are constantly listening for signals, coming from distant alien civilizations.
The search for extraterrestrial intelligence, SETI, is an effort to find artificial-looking
electromagnetic radiation that might have come from a technologically advanced civilization,
in a far-away solar system.
For decades though, the field was constrained by having hardly any data at all.
But that changed in 2015, when billionaire Yuri Milner funded the biggest SETI programme
ever, in Berkeley, California: the Breakthrough Listen project to search one million stars
for signs of intelligent life.
Using telescopes in West Virginia, Australia and South Africa, the project looks for radio
emissions that come from the direction of a star, and that change steadily in frequency,
as would happen if an alien transmitter were on a planet, moving with respect to Earth.
The trouble is, that these searches yield a blizzard of data, including false positives,
produced by Earthly interference from mobile phones, GPS, and other aspects of modern life.
The biggest challenge in looking for SETI signals is not at this point getting the data,
but differentiating signals from human, or Earth technology, from the kind of signals
we’d be looking for from technology somewhere else out in the Galaxy.
And, going through millions of observations manually isn’t practical.
The solution?
Artificial Intelligence.
And, a new machine learning method has found eight previously undetected “signals of
interest” and they are very, very interesting.
The eight new signals are coming from stars that are relatively closer to earth and could
be indications of alien intelligence on other planets.
And those targets – and others like them – mean that artificial intelligence could
allow us to finally find signals of life beyond Earth, according to researchers.
Much of the hunt for extraterrestrial intelligence looks for “technosignatures”, or signals
that could have come from alien technology, accidentally or on purpose.
But scientists struggle to find those technosignatures in part because there are so many interesting
candidates, much of which comes from interference.
The new system is intended to allow researchers to comb through the vast amount of data coming
to us from the universe, and help us more quickly pick through to find signals that
might be of interest.
It could also let researchers filter out false positives, which can happen when instruments
pick up interference from human technology, for instance.
It has already found eight “promising extraterrestrial intelligence signals of interest not previously
identified”, researchers write in a new paper describing the system.
However, repeated observations of those targets has not yet resulted in the re-detection of
signals that are similar, scientists say.
Most of the search for techno signatures has focused on radio frequencies, because they
travel easily through space and systems for sending and detecting them can be built relatively
easily.
In particular, researchers look for narrowband radio signals that can be more easily picked
apart from natural radio emissions that occur regularly throughout the universe.
The new system hunted through data that has been collected on those radio signals, which
have come from throughout the universe.
It is described in a paper, ‘A deep-learning search for technosignatures from 820 nearby
stars’.
Scientists searched through 115 million snippets of data, and found almost 3 million signals
of interest.
The researchers note that is probably an “overcount” given the way the system hunts through those
snippets, and many of the signals probably do come from interference.
After filtering out signals that appeared to be false positives, they were left with
20,515 signals.
Of those, they found eight “signals of interest” that grabbed the interest of researchers.
The eight signals come from five different stars, all between 30 and 90 light years from
Earth.
There are a variety of strange radio signals that have been detected in space, and scientists
continue to study them in order to understand their origin and nature.
Fast Radio Bursts aka FRBs, are extremely short bursts of radio waves, lasting only
a few milliseconds.
They are extremely bright and can be detected from billions of light years away.
Scientists are still trying to determine the cause of FRBs, but some theories include supernovae,
black holes, or even extraterrestrial civilizations.
Overall, strange radio signals can offer an exciting opportunity for scientists to explore
the unknown and potentially discover new phenomena in the universe.
However, it's also important to approach these signals with a healthy dose of scepticism
and to critically evaluate any claims about their origin and nature.
Back in 1977, while reviewing a recorded data, astronomers discovered a strong
narrowband radio signal, detected by the Ohio State University’s Big Ear radio
telescope.
The signal appeared to come from the direction of the constellation Sagittarius, and
bore the expected hallmarks of extraterrestrial origin.
Astronomer Jerry R Ehman, who detected the signal, was so impressed by the result,
that he circled on the computer printout, the reading of the signal’s intensity, and
wrote the comment: Wow, beside it, leading to the event’s widely used name.
The entire signal sequence lasted for the full 72-second window, during which Big Ear
was able to observe it, but has not been detected since, despite several subsequent
attempts.
Many hypotheses have been advanced on the origin of the emission, including natural
and human-made sources, but none of them adequately explain the signal.
The Wow signal, remains the strongest candidate for an extraterrestrial radio
transmission, ever detected.
Since then, we have detected countless radio signals coming from several directions.
One of them, came from the direction of Proxima Centauri, arising hopes in the
hearts of several people, that an alien civilization from our nearest star was trying to
contact us.
It turned out, that the radio waves were created by human-made technological
anomalies.
And now, astronomers have captured a radio signal from the most distant galaxy so far.
The radio signal captured was found to have a wavelength of 21 cm line, researchers from
Montreal and India revealed in a new study.
This signal came from the most distant known galaxy SDSSJ0826+5630 and may help researchers
look back at the early universe.
Astronomers used the Giant Metrewave Radio Telescope in India to detect the signal.
It is the first time this type of radio signal has been detected from such an immense distance.
"A galaxy emits different kinds of radio signals," says Arnab Chakraborty, a post-doctoral researcher
at McGill University under the supervision of Professor Matt Dobbs.
"Until now, it’s only been possible to capture this particular signal from a galaxy nearby,
limiting our knowledge to those galaxies closer to Earth," Chakraborty added.
He noted that researchers used a naturally occurring phenomenon called gravitational
lensing to capture a faint signal from a "record-breaking distance."
Gravitational lensing term was coined by Albert Einstein and describes when closer objects
act as a magnifying glass for distant objects.
Essentially gravity warps and magnifies the light of distant background galaxies.
"This will also help us understand the composition of galaxies at much greater distances from
Earth," Chakraborty said.
In the study, the researchers said they were able to observe the distant galaxy's atomic
mass of its gas content.
And what they found was that this particular galaxy is almost twice the mass of the stars
visible to us.
The team said the detected signal was emitted from the faraway galaxy when the universe
was only 4.9billion years old.
This allowed the researchers to glimpse into the "secrets of the early universe", a press
release from McGill University reported.
"It’s the equivalent to a look-back in time of 8.8 billion years," explained Chakraborty.
In the future, researchers hope to use Artificial Intelligence to scan through and pick data
quickly.
Advancements in AI will take humanity to new leaps and bounds, and the future looks absolutely
amazing.
What do you guys have to say?
Do you think we will ever make contact with an alien civilization?
And will it be Artificial Intelligence that will finally help us find an answer to the
biggest question: are we alone?
Drop in your comments to let us know, and don’t forget to subscribe to Lab 360, there
is a little space for everyone here.