Alien-hunters crack cosmic code with new ‘twinkle check’ that spot actual area alerts
Alien-hunters are focusing their telescopes on ‘pulsar’ stars to time their twinkles, giving them a new tool to sift through space signals and spot messages from other forms of life
Alien-hunters have found a new way to pick up messages from extra-terrestrials by measuring the ‘twinkle’ from pulsar stars (Image: Getty Images)
Boffins at the SETI (Search for Extraterrestrial Intelligence) Institute have found a new way to sort through the signals reaching us from space to find messages from aliens.
By pointing their telescope on a “pulsar” star for 10 months, the ET-hunters have been able to track the tiny changes in radio signals from these stars, which send out thousands of pulses every second.
They found that gas between stars can shift the signal’s arrival time by billionths of a second. By measuring this twinkle, they have honed the “clock” the pulses provide and found “wonderful tools” to find out about “the universe and our own stellar neighbourhood”.
The study started in February 2023, when Grayce Brown and her team at SETI started tracking the pulsar PSR J0332+5434. This fast-spinning remnant of a neutron star is over 3,000 light-years from Earth and the brightest pulsar visible to the SETI-operated Allen Telescope Array in California, USA.
The team tracked subtle changes in radio signals for 10 months to read its subtle “twinkle”. Their research found that gas between stars shifts the arrival time of a pulsar’s signal by billionths of a second.
These tiny delays help experiments that use pulsars as ultra-precise cosmic clocks. They’re especially handy for detecting low-frequency gravitational waves and searching for signs of alien life.
“Pulsars are wonderful tools that can teach us much about the universe and our own stellar neighbourhood”, study lead author Grayce Brown of the SETI Institute said in a statement reported by Space.com. She further stated: “Results like these help not just pulsar science, but other fields of astronomy as well, including SETI.”
From nearly 400 observations, the team saw how radio waves from the pulsar’s poles travel through space, passing through clouds of charged gas, primarily free electrons that bend, scatter, and slightly delay the signal. This scintillation in the radio signals mirrors how stars appear to twinkle in Earth’s atmosphere, according to the study.
As the earth, the pulsar, and the interstellar gas between them move relative to each other, bright and dim patches form and shift. These patterns affect when the pulses arrive, creating delays in tens of nanoseconds.
However, these tiny discrepancies between the predicted and observed arrival times of pulsar pulses can have outsized consequences. If delays from interstellar gas are not properly accounted for, they can hide the faint signals the alien-hunters are trying to find.
The boffins say the findings provide a valuable tool for SETI researchers trying to sort out cosmic signals from interference coming from Earth. “Noticeable scintillation can help SETI scientists distinguish between human-made radio signals and signals from other star systems,” the institute said in a statement.
“We need some way to differentiate between signals coming from Earth and signals coming from beyond our Solar System,” Brown told The Debrief. He continued: “Because of this research, we know how much scintillation to expect from a radio signal traveling through this pulsar’s region of interstellar space.
“If we don’t see that scintillation, then the signal is probably just interference from Earth.” The study was published on December 10 in The Astrophysical Journal.
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