Civilizations Could Time Their Communications Based on the Movement of a Single Star

Image of the galactic centre. For the interferometric GRAVITY observations the star IRS 16C was used as a reference star, the actual target was the star S2. The position of the centre, which harbours the (invisible) black hole known as Sgr A*,with 4 million solar masses, is marked by the orange cross.

The Search for Extraterrestrial Intelligence has been ongoing for decades at this point. Despite that, we have yet to find any rock-hard evidence of a signal from an alien civilization. When asked about this, experts point out just how little of the overall signal space we’ve analyzed. A signal could be coming from anywhere in the sky, at any frequency, and might not be continuous. Constraining the “search space” could help us find a signal faster, but what could we use to constrain it? It’s hard to think like an alien intelligence, let alone to mimic them.

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Starshot … Not? Get a Reality Check on the Search for Alien Civilizations

Zine Tseng as Chinese radio astronomer, sitting at control panel for antenna
Zine Tseng plays a Chinese radio astronomer in "3 Body Problem." (Credit: Ed Miller / Netflix © 2024)

Fortunately, the real-world search for signs of extraterrestrial civilizations doesn’t have to deal with an alien armada like the one that’s on its way to Earth in “3 Body Problem,” the Netflix streaming series based on Chinese sci-fi author Cixin Liu’s award-winning novels. But the trajectory of the search can have almost as many twists and turns as a curvature-drive trip from the fictional San-Ti star system.

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How Long Will Advanced Civilizations Try to Communicate With Us?

Technosignature research is heating up, with plenty of papers speculating on the nature, and sometimes the longevity, of signals created by technically advanced extraterrestrial civilizations. While we haven’t found any so far, that isn’t to say that we won’t, and a better understanding of what to look for would undoubtedly help. Enter a new paper by Amedeo Balbi and Claudio Grimaldi, two professors at the Universita di Roma Tor Vergata and the Ecole Polytechnique Federale de Lausanne, respectively. They have taken a statistical model to the problem of understanding how old a technosignature might be before we are likely to find it – and their answer is, surprisingly young.

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The SETI Ellipse Tells Us Where to Search for Extraterrestrial Civilizations

The SETI Ellipsoid (Image credit: Zayna Sheikh)

Of all the questions that remain unanswered, the question of life in the Universe is surely the one that captures our attention the most. In a Universe whose observable edge is 46 billion light years away, is it even conceivable that we are alone, the sole planet among the millions and perhaps billions that are out there, where life has evolved, an oasis of life in the cosmic ocean. In the search for alien civilisations, researchers have proposed that it may be possible to use bright galactic events like supernovae to act as a focal point for civilisations to announce their presence! 

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China’s FAST Observatory is Playing a Key Role in the Search for Aliens

China's FAST telescope

Some years ago I rememeber running the SETI at Home screensaver and would watch it for hours to see if any peaks appeared naively thinking they might be signals from an alien civilisation! There is no doubt that the search for extraterrestrials (ET) has captivated the minds of many people across the years. The search has of course to date, been unsuccesful despite multiple observations that seem to suggest the conditions for life across the cosmos may actually be more common than we first thought. Now Chinese agencies are funding projects to use the Five Hundred Meter Aperture Spherical Telescope (FAST) to conduct searches for alien signals.

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After all of This Time Searching for Aliens, is it The Zoo Hypothesis or Nothing?

The Karl Jansky Very Large Array at night, with the Milky Way visible in the sky. Credit: NRAO/AUI/NSF; J. Hellerman

In 1950, during a lunchtime conversation with colleagues at the Los Alamos National Laboratory, famed physicist Enrico Fermi asked the question that launched a hundred (or more) proposed resolutions. “Where is Everybody?” In short, given the age of the Universe (13.8 billion years), the fact that the Solar System has only existed for the past 4.5 billion years, and the fact that the ingredients for life are everywhere in abundance, why haven’t we found evidence of extraterrestrial intelligence by now? This came to be the basis of Fermi’s Paradox, which remains unresolved to this day.

Interest in Fermi’s question has been piqued in recent years thanks to the sheer number of “potentially habitable” exoplanets discovered in distant star systems. Despite that, all attempts to find signs of technological activity (“technosignatures”) have come up empty. In a recent study, a team of astrobiologists considered the possible resolutions and concluded that only two possibilities exist. Either extraterrestrial civilizations (ETCs) are incredibly rare (or non-existent), or they are deliberately avoiding contact with us (aka. the “Zoo Hypothesis“).

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Trying to Communicate with Whales is Like Talking to Extraterrestrials

Communicating between species isn’t something that only has to take place between space-faring civilizations. There are plenty of species here on our home planet that communicate using a variety of sights, sounds, and smells. We’re only starting to unlock the secrets of how to understand and respond to these types of foreign languages. Researchers at the SETI Institute think that doing so might be a good test for whether we’ll be able to communicate with extraterrestrials if we ever get the chance to.

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Breakthrough Listen Scans Entire Galaxies for Signals From Extremely Advanced Civilizations

Breakthrough Listen has released the results of its latest survey - the center of 97 galaxies!

In 1960, Dr. Frank Drake led the first Search for Extraterrestrial Intelligence (SETI) experiment at the National Radio Astronomy Observatory in Green Bank, West Virginia. In the more than sixty years that have since passed, astronomers have conducted multiple surveys in search of technological activity (aka. technosignatures). To date, Breakthrough Listen is the most ambitious SETI experiment, combining data from the Robert C. Byrd Green Bank Telescope, the Parkes Murriyang Telescope, the Automated Planet Finder, and the MeerKAT Radio Telescope and advanced analytics.

The program includes a survey of the one million closest stars to Earth, the center of our galaxy and the entire galactic plane, and the 100 closest galaxies to ours. In a recent paper, members of Breakthrough Listen presented the results of their radio technosignature search of the centers of 97 nearby galaxies observed by the Robert C. Byrd Green Bank Telescope. This search was one of the largest and broadest
searches for radio evidence of extraterrestrial intelligence ever undertaken, surveying trillions of stars at four frequency bands. Unfortunately, no compelling candidates were found.

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Why Don't We See Robotic Civilizations Rapidly Expanding Across the Universe?

The central region of the Milky Way, also known as the Zone of Avoidance. Credit: ESO/S. Brunier

In 1950, while sitting down to lunch with colleagues at the Los Alamos Laboratory, famed physicist and nuclear scientist Enrico Fermi asked his famous question: “Where is Everybody?” In short, Fermi was addressing the all-important question that has plagued human minds since they first realized planet Earth was merely a speck in an infinite Universe. Given the size and age of the Universe and the way the ingredients for life are seemingly everywhere in abundance, why haven’t we found any evidence of intelligent life beyond Earth?

This question has spawned countless proposed resolutions since Fermi’s time, including the infamous Hart-Tipler Conjecture (i.e., they don’t exist). Other interpretations emphasize how space travel is hard and extremely time and energy-consuming, which is why species are likely to settle in clusters (rather than a galactic empire) and how we are more likely to find examples of their technology (probes and AI) rather than a species itself. In a recent study, mathematician Daniel Vallstrom examined how artificial intelligence might be similarly motivated to avoid spreading across the galaxy, thus explaining why we haven’t seen them either!

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SETI Researchers Just Got a $200 Million Gift to Search for Life

SETI Institute Logo
The SETI Institute

Among the many outstanding questions in science, ‘Are We Alone’ must be the one that captivates scientists and public alike.  I have very fond memories watching the SETI screensaver on my laptop churn through data while and wondering if the big peaks in the fascinating looking graphs meant something had been found! That was a good few years back now but the search for ET continues.  One such organisation spearheading the hunt is the SETI Institute and they have just announced a whacking great alien busting $200 million gift. 

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