Scientists have found 'evidence' of advanced alien civilisations

It’s long been assumed that if alien civilisations do exist, they’re a hell of a lot smarter than we are.

And yet, whilst a team of scientists agrees that this is probably true, they’ve also proven that they’re clever enough themselves to track these ETs down.

The international team of researchers, based in Sweden, India, the US and the UK, have devised a way to search for unimaginably complex extraterrestrial megastructures, known as Dyson spheres.

And, after sifting through millions of potential space objects, they believe that they’ve identified seven of these behemoths lurking in the cosmos.

To the uninitiated, a Dyson sphere is a hypothetical engineering feat that only a civilisation far more advanced than our own would be capable of building.

The prospect of such a construction was proposed by physicist and astronomer Freeman J. Dyson back in 1960, who envisaged them as a solar-system-sized shell consisting of a “swarm of objects” that could travel on independent orbits around a star, such as our sun.

The idea is that the aliens commandeering this multi-faceted sphere would use it to harness the energy of the star to fulfil the escalating energy needs of its technologically sophisticated people.

Dyson spheres are hypothetical megastructures that could harness the power of an entire star, leaving technosignatures that could be detected by humanity(iStock)

Now, the international group of scientists say they’ve worked out how to detect technosignatures from a potential Dyson sphere, and they’ve named their efforts Project Hephaistos (after the Greek god of fire and sculpture).

In a paper published on 6 May, the team, led by Matías Suazo, of Sweden’s Uppsala University, details how they analysed data gathered by the European Space Agency’s Gaia map of stars, as well as the 2MASS infrared astronomical survey and NASA’s WISE infrared astronomy space telescope to carry out their work.

From these three surveys, they investigated around 5 million sources “to build a catalogue of potential Dyson spheres," they explained that they were searching for partially completed spheres that would emit excess infrared radiation.

"This structure would emit waste heat in the form of mid-infrared radiation that, in addition to the level of completion of the structure, would depend on its effective temperature," Suazo and his colleagues write in their paper.

The issue here is that plenty of other natural objects emit excess infrared radiation, including nebulae and background galaxies, as Universe Today notes.

Nebulae and other celestial objects also emit excess infrared radiation(iStock)

And so, as you’d hope, Suazo and his colleagues created a “specialised pipeline” to sift the possible wheat from the chaff.

"[This] pipeline has been developed to identify potential Dyson sphere candidates focusing on detecting sources that display anomalous infrared excesses that cannot be attributed to any known natural source of such radiation," the researchers stress.

Then, they subjected the list of star candidates to further filtering, based on factors including H-alpha emissions, optical variability, and astrometry.

They managed to whittle this list down to 368 sources before, of these, 28 were rejected as blends, 29 were rejected as irregulars, and four were rejected as nebulars.

This left just seven potential Dyson spheres out of the five million-odd initial objects, and the researchers feel confident that these seven are legitimate.

"All sources are clear mid-infrared emitters with no clear contaminators or signatures that indicate an obvious mid-infrared origin," they say.

Nevertheless, the team acknowledges that there could be other reasons why the group is emitting excess infrared.

"The presence of warm debris disks surrounding our candidates remains a plausible explanation for the infrared excess of our sources," they admit.

Nevertheless, their candidates seem to be M-type (red dwarf) stars, and debris disks around M-dwarfs are very rare, according to Universe Today.

The team's shortlist of Dyson sphere candidates appear to be M dwarf stars(NASA)

The scientists went on to conclude that these “seven apparent M dwarfs [exhibit] an infrared excess of unclear nature that is compatible with our Dyson sphere models.”

The researchers note that follow-up optical spectroscopy would help better understand these seven sources.

"Additional analyses are definitely necessary to unveil the true nature of these sources," they emphasise.

But who knows what such analyses could, ultimately, reveal…

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