What Are Alien Dyson Spheres, Why Are They So Janky, and Why Are They Doomed to Go Undetected?
In the 1960s, physicist Freeman Dyson proposed that advanced alien civilizations could be building enormous megastructures around a star to harness its energy.
Such a move would allow a civilization to advance from a Type I to a Type II civilization on the Kardashev scale, harvesting the energy available from a star directly instead of from a given planet's surface.
These shells, dubbed Dyson spheres, could be giving off distinct technosignatures, astronomers have suggested, making them observable, potentially, from many light-years away.
But despite our best efforts, we have yet to make first contact, let alone with an alien-built megastructure siphoning off the energy released by a star.
And, as New Scientist reports, there could be a good reason for that. According to Brian Lacki, a scientist involved with the Breakthrough Listen Initiative — which searches for evidence of extraterrestrial civilizations — Dyson spheres may destroy themselves long before we can encounter one.
In a yet-to-be-peer-reviewed paper, Lacki proposed that having satellite-like objects swarming a star all at once could result in a disastrous, cascading effect in the case of a collision.
"When you have a whole bunch of things moving together like that in a swarm, a natural question is going to be, do they sometimes bump into each other?" Lacki told New Scientist. "At their orbital speeds, that can be disastrous."
In many ways, the risk of that kind of scenario is already playing out in the orbit of our own planet. Scientists have long warned that satellites circling the Earth could collide with each other or with one of the countless pieces of space junk, potentially triggering a knock-on effect, called Kessler syndrome.
Experts have warned that it's only a matter of time until a collision could trigger a catastrophe.
According to Lacki, aliens would have to tread very carefully to ensure that satellites aren't crossing each other's paths.
"You just can't have that much material around a star without it colliding with itself and eventually shredding itself to pieces, unless each of those swarm components is careful about managing its orbit," Penn State astrophysics professor Jason Wright, who was not involved in the research, told New Scientist.
Lacki's conclusion leaves an intriguing possibility: we may still be able to detect the signatures of already collapsed megastructures orbiting distant stars. However, without that visible technosignature, they would be incredibly difficult to spot.
As far as harnessing the power of the Sun is concerned, researchers have previously found that we would need to demolish a Jupiter-sized planet to build a Dyson sphere around our host star, an enormous — and likely risky — endeavor.
More on Dyson spheres: Scientists Identify Seven Star Systems That May Be Hosting Alien Megastructures
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Rare Jupiter-sized planet discovered 3,200 light-years away using Einstein's space-time warping method
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The White House, in issuing its slashed budget plan for NASA, never provided a logical rationale for torpedoing some of the agency's world-leading missions to survey and image the solar system. Its inscrutable sinking of some of these vanguard voyages was unveiled with the terseness of a telegram: 'Operating missions that have completed their prime missions (New Horizons and Juno) and the follow-on mission to OSIRIX-REx, OSIRIS-Apophis Explorer, are eliminated.' The asteroid-hunter OSIRIS spacecraft, shown here at the Kennedy Space Center in Florida, is one of ... More the trailblazers set to be terminated by the White House. (Photo by Bruce Weaver / AFP) (Photo by BRUCE WEAVER/AFP via Getty Images) AFP via Getty Images The OSIRIS spacecraft, which had been slated to rendezvous with the closely approaching Apophis asteroid ahead, is a precursor mission to defending the Earth's eight billion citizens against doomsday cosmic strikes by colossal comets or asteroids of the future. The robotic photographer Juno has snapped an endless kaleidoscope of imagery as it floats around Jupiter. Scientists at NASA's Jet Propulsion Lab have posted raw impressions of the orb and its moons and invited 'citizen scientists' to Photoshop and launch them across the cybersphere. In the process, they are becoming part of the spacefaring civilization that is spreading out across the globe. Model of the $1-billion Juno spacecraft, which is now orbiting and photographing Jupiter (Photo by ... More) Getty Images During its own space odyssey, New Horizons has astounded stargazers, students and scholars worldwide with its technicolor panoramas of Pluto, covered in surreal ice-fields and cryo-volcanoes, and its age-old companion Charon. The twin netherworlds—named after the mythical Greek god of the underworld and the pilot who shuttled souls across the river Styx—circle more than five billion kilometers distant from the sun, along an orbit that Stern's Pluto expedition took nine years to reach. Now, even as it whizzes beyond all of the classical planets, New Horizons, and its future, has entered the purgatory of potential excommunication by mission controllers—and their masters—six worlds away. The New Horizons spacecraft, now speeding through the outer solar system, could be jettisoned under ... More a White House plan that would destroy American leadership in planetary science missions. (Photo by Heritage Art/Heritage Images via Getty Images) Heritage Images via Getty Images 'This is a vast and tragic mistake,' Stern says, 'because the issue is larger than just NASA, it also affects U.S. world leadership [and] responsible government that protects taxpayers from waste like this.' The administration's crash-and-burn dismissal of the solar system's trailblazing robotic discoverers has triggered trepidation across NASA, whose ranks of pioneering scientists are likewise set to be culled. Within NASA, Alan Stern is a pole star of cutting-edge exploration, helping guide more than two dozen missions. After his New Horizons spacecraft rendezvoused with Pluto, the agency bestowed its highest honor on him - the NASA Distinguished Public Service Medal. 'Stern led the team that returned remarkable imagery and other data from the Pluto system last summer, generating headlines worldwide and setting a record for the farthest world ever explored,' NASA's leaders said. "New Horizons represents the best of humanity and reminds us of why we explore,' added Jim Green, NASA's director of planetary science. "The first flyby of Pluto is a remarkable achievement.' Being given the chance to lead the close encounter with Pluto, Stern said on accepting the award, 'has been the greatest honor of my lifetime.' Around the same time, NASA film-makers paid tribute to Stern, his 2000+ Pluto mission colleagues, and the target of their interplanetary expedition in the captivating documentary ' The Year of Pluto .' Stern has himself chronicled his trek across the twilight reaches of the star system in a series of fascinating books, including Pluto and Charon: Ice Worlds on the Ragged Edge of the Solar System and Chasing New Horizons, and in a torrent of acclaimed papers . Scholar Stern predicts that if the White House's proposed death sentence for flotillas of pathfinding space missions is actually carried out, that would mark the decline and fall of NASA's planetary science breakthroughs, and the comparative rise of its competitors in the renewed space race of the 2020s. If NASA's funding and inter-planet journeys are decimated, he tells me, 'These cuts will absolutely destroy U.S. leadership in all the space sciences.' 'This is tragically misguided.' The potential death knell for an armada of space discovery missions has been reverberating not just across NASA, but also throughout the U.S. universities that help conceive or design these flights. 'Certainly termination of the New Horizons mission would be terrible,' says Kip Hodges , who as founding director of Arizona State University's School of Earth and Space Exploration helped transform the university into one of the top American space studies centers. 'This a real frontier mission at this point,' he tells me in an interview, 'delivering important new information about distant parts of our Sun's heliosphere.' Congress has the power to save NASA and its leading-edge robotic explorers across the solar system ... More (Illustration by Tobias Roetsch/Future Publishing via Getty Images) Future Publishing via Getty Images Professor Hodges , one of the top space scholars in the U.S., predicts that the Swords of Damocles now hanging above New Horizons and other new-frontier flights could still be lifted. If the White House plan to cut away at NASA and its revolutionary planetary scouting missions were enacted as is, he predicts, 'a great many folks in industry, the NASA labs, and academia will be disappointed.' Yet he adds that 'the budget for NASA evolves over several stages,' with the president's initial proposal just one of competing models—one that could be rejected as the Senate and House of Representatives look afresh at NASA's missions, goals and funding. After the twin chambers reach a consensus on reshaping NASA for the next phase of its evolution, Professor Hodges adds, 'Quite often, the appropriated budget is not the president's budget.' That means space aficionados across America who seek to overturn the president's capital sentence on NASA's boundary-breaking missions have a clear channel of recourse, Stern says. Would-be petitioners for a reprieve, he advises, 'should contact their elected representatives in Congress and tell them this is a huge mistake.'
