Scientists searching for aliens investigate radio beam “from a nearby star” | Space-bar

Astronomers behind the most extensive search for extraterrestrial life are investigating an intriguing radio show that appears to have come from the direction of Proxima Centauri, the closest star to the sun.

The narrow beam of radio waves was picked up during 30 hours of observations by the Parkes telescope in Australia in April and May last year, the Guardian understands. The analysis of the beam has been going on for some time and scientists have not yet identified a terrestrial culprit, such as ground equipment or a passing satellite.

It is common for astronomers in the $ 100 million Breakthrough Listen project to see strange explosions from radio waves with the Parkes telescope or the Green Bank Observatory in West Virginia, but all have so far been attributed to man-made or natural interference. sources.

The latest “signal” will probably have a trivial explanation, but the direction of the narrow beam, around 980 MHz, and an apparent change in its frequency that is said to be consistent with the motion of a planet have been added to the tempting nature of the finding. Scientists are now preparing a paper on the beam, called BLC1, for Breakthrough Listen, the project to look for evidence of life in space, the Guardian understands.

The beam, which appears to have come from the direction of Proxima Centauri, a red dwarf star 4.2 light-years from Earth, was not seen from the initial observation, according to an individual in the astronomy community who requested anonymity because the work is ongoing. . “He is the first serious candidate from” Wow! signals, ”they said.

“Wow! signal ”was a short-lived narrowband radio signal taken over by an alien intelligence search, or Seti, by the Ohio Big Ear Radio Observatory in 1977. The unusual signal, which earned its name after astronomer Jerry Ehman wrote, “Wow! ”Next to the data, unleashed a wave of enthusiasm, although Ehman warned about drawing“ vast conclusions from half-vast data ”.

An artist's impression of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system.
An artist’s impression of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system. Photo: ESO / M. Cereal knives / Reuters

Launched in 2015 by Yuri Milner, a Silicon Valley-based science and technology investor, the Breakthrough Listen project listens to millions of stars closest to Earth, hoping to detect stray or intentional extraterrestrial broadcasts. The 10-year effort was announced at the Royal Society of London when the late Stephen Hawking called the work “important.” Speaking at the event, Hawking, who saw the future of humanity in the stars, said: “Humanity has a deep need to explore, to learn, to know. We also happen to be sociable creatures. It is important for us to know if we are alone in the dark. “

The challenge for Breakthrough Listen astronomers and others dedicated to finding intelligent life in the sky is to identify potential “techno-signatures” amid the incessant stuttering of radio waves from Earth’s equipment, natural cosmic phenomena, and orbiting hardware around the planet. It is not an easy task. In 1997, American alien hunter Jill Tarter, who inspired Ellie Arroway’s character in the film Contact, detected a potential signal, but was later found to be broadcasting from a Soho spacecraft antenna, a joint mission to observe the Sun. to NASA and the European Space Agency.

Although too weak to be seen with the naked eye, Proxima Centauri was heavily controlled by astronomers. It is known that at least two planets orbit the star. One is a gas giant, and the other is believed to be a rocky world about 17% more massive than Earth. Known as Proxima b, the planet orbits its star every 11 days and is located in the so-called “habitable zone”, where the temperature is suitable for water to flow and gather.

But this does not mean that water is present on Proxima b. Despite its seemingly comfortable location, the planet can be very hostile to life. In 2017, NASA scientists used computer models to show that if Proxima b had an Earth-like atmosphere, it could be easily stripped of intense radiation and solar flames unleashed by its parent star. Under this beating, the 4 billion-year-old planet could have lost its entire atmosphere in 100 million years.

Pete Worden, former director of the Ames Research Center in California and executive director of Breakthrough Initiatives, said it’s important to wait and see what the scientists in the project concluded: “The Breakthrough Listen team has detected several unusual signals and is investigating carefully. These signals are a probable interference that we cannot yet fully explain. Additional analyzes are currently being performed. “

Others are cautious, to say the least. “The chances of this being an artificial signal from Proxima Centauri seem staggering,” said Lewis Dartnell, an astrobiologist and professor of scientific communication at the University of Westminster. “We’ve been looking for extraterrestrial life for so long now, and the idea that it might turn out to be on the doorstep in front of us in the next star system is piling improbability upon improbability.

“If there was intelligent life there, it would almost certainly have spread much wider across the galaxy. The chances of the only two civilizations in the entire galaxy being neighboring, among 400 billion stars, absolutely stretch the limits of rationality. “

It’s not just the statistics that look bad. The next b is so close to its parent star that it is blocked in an orderly fashion, just as the moon is Earth. One part is the eternal day, the other in perpetual darkness. “It’s hard to imagine how you can have a stable climate system and all the things you need to get from bacteria that are resistant to intelligent forms of animal life that certainly aren’t,” Dartnell added. “But I’d like to be wrong.”

Is anyone there?

1899 The search for life elsewhere has been long and deeply unproductive, at least in terms of trying to find extraterrestrial civilizations. In the late 19th century, Serbian-American inventor Nikola Tesla believed he had intercepted radio messages from Mars. As far as scientists know from countless observations and decades of visits by robotic probes, there is no life on Mars.

1967 Dame astrophysicist Jocelyn Bell Burnell was examining a mountain of data from a new radio telescope she had helped build when she saw an unusual signal. It was weak, but it was constantly repeated. After ruling out interference from terrestrial sources, the team considered the men green. The real source turned out to be a pulsar, a spinning neutron star that emits beams of radio waves like a celestial beacon.

1977 It happened to be the year Star Wars was released when Jerry Ehman, an astronomer at Ohio State University’s Big Ear Radio Telescope, found something curious while scanning the skies for extraterrestrial broadcasts. The telescope observed a group of stars called Chi Sagittarii when it recorded a 72-second pulse of radio waves. Ehman circled the data and wrote “Wow!” on the display, giving the name of the signal. Scientists have proposed possible sources, but the signal remains inexplicable.

2003 The Seti @ home project, led by the University of California at Berkeley, with observations from the Green Bank radio telescope and the recently crashed Arecibo telescope, also revealed an interesting signal. The 1420 MHz radio wave explosion, known as SHGb02 + 14a, was observed three times before disappearing. The signal is in the quiet area of ​​the “water hole” of the electromagnetic spectrum, which scientists consider an attractive band for extraterrestrial civilizations to transmit interstellar signals.