Scientists believe there may be Dyson spheres out there in our galaxy, having identified at least seven stars in the Milky Way where these megastructures could be built.

He theorized that such artificial radiation sources could indicate the existence of alien life. One potential source for such artificial radiation was a hypothetical megastructure around a star that would absorb heat and energy from the star and then re-radiate waste energy out into space.

Dyson’s idea was that such alien civilizations would look to try and use all the power radiating from the star in their solar system to meet their needs. His theoretical shell of structures around the star would be able to absorb and exploit huge amounts of solar energy. The star-facing surfaces of these structures would also be habitable, solving power and space issues in one go.

A Dyson sphere famously appeared in a 1992 episode of “Star Trek: The Next Generation” titled “Relics.” As one of the most popular television shows of all time, this appearance no doubt helped further cement the Dyson sphere in the public consciousness.

Those searching for Dyson spheres look for spikes in these infrared wavelengths known as infrared excess emissions (IEEs) when looking at the electromagnetic spectra of distant stars. Such technological signatures, along with radio waves, artificial light, and greenhouse gasses, are potential signatures of alien life.

Incredibly, this computer program identified seven stars as strong candidates for the presence of Dyson spheres. This is not the only study to find potential IEEs. A similar study uploaded to the pre-print server arXiv identified 53 stars as potential sources of IEEs and, therefore, potential Dyson sphere sites.

But it’s impossible to rule out other explanations for these IEEs. Discs of extreme debris around stars would also get superheated and send out infrared radiation. So just because scientists have found IEEs, that doesn’t mean they’ve definitely found Dyson spheres.

Any civilization capable of constructing a Dyson sphere would be massively advanced — far beyond our own technical capabilities. If a civilization out there was capable of constructing such a huge megastructure in space, then we have to start asking questions like: Are they capable of traveling the stars? Are these aliens who could potentially make contact with us?

Missing matter is, in essence, the stuff in the universe that we have not found yet that accounts for the mass that that we need to explain the movements of galaxies under the laws of gravity. Missing matter takes the form of dark matter and more regular materials like hydrogen or helium.

According to IFL Science, it does not seem likely. Given that the material would need to come from somewhere for a Dyson sphere to work, it is hard to imagine that an advanced civilization would scoop up matter and solidify it.

This sphere would be thin to the point of being gravitationally unstable and the only way to stop it from collapsing would be by using huge amounts of energy. This makes the entire idea a net loss.

Scientists will look to use powerful instruments to try and take more accurate readings from the seven stars they identified as giving out IEEs. By using these tools on these specific stars, scientists will look for other potential signs of intelligent alien life in these star systems.

But it’s conceivable that scientists might look at ways of capturing greater amounts of solar energy in space. Humanity’s needs for energy are only growing, and the sun is a massive potential power source. However, only a tiny fraction of this power makes it to the Earth’s surface. If we covered the Earth in solar panels, we wouldn’t even capture a tenth of a billionth of the solar energy our sun produces.

But this gigantic closed sphere isn’t what Dyson originally envisaged when he spoke about the potential for harnessing the power of a star. His idea of some form of habitable megastructure close to a star remains something that, though still almost inconceivable practically, has enough “science fact” to it to keep it in the minds of physicists.

Barnard College’s theoretical cosmologist, Dr. Janna Levin, has inferred that the heat signatures could be explained by factors like planetary collisions. Other suggestions from Dr. Levin include a young star with material spinning around it in a disk or a distant galaxy behind some of the stars could be the reason behind the heat.

“Dyson spheres are more likely to be Dyson swarms – a vast collection of solar-energy collecting satellites, each on independent orbits around the sun. Heat signatures are so generic in nature that it’s far from a smoking gun and there are many possible natural explanations,” Levin told Salon.

Astrophysicist and science writer, Dr. Ethan Siegel, said that stars may emit large amounts of energy, but the temperature they radiate at is determined by the size of the star’s surface area from which the energy is emitted. Dr. Siegel is also skeptical about the Dyson spheres.

Dr. Erik Zackrisson, associate astronomy professor at Uppsala University, is not only sceptical of the existence of Dyson spheres, but also that the existence would prove that there is intelligent extraterrestrial life. He shared the view of Siegel that the most fantastical outcome is seldom the most likely. Most of the time, it is a rather mundane field.

However, he also said that he hopes these stars are confirmed to have intrinsic infrared excess fluxes, even if it “boils down to extreme astrophysics rather than aliens”.

A more recent study has shown that at least three of the seven stars in question are hot DOGs which are enormous thickets of dust. The key information here is that warm dust is particularly adept at emitting infrared radiation.

It means that the unusually high amount of infrared radiation emitted from these stars are just because they are surrounded by warm dust, as opposed to an extraterrestrial megastructure that collects solar energy.

“Alternatively, it could just be normal old astrophysics at play, with no aliens, no megastructures, no Dyson spheres, and nothing exotic. When you have an extraordinary explanation for the same observed phenomenon, you really need more evidence to favor the former explanation over the latter one, and we don’t have that.”

Levin said: “Is someone looking at us wondering if they’ve found signatures of intelligent life? Fascinating.  However, we’ve not been at this space industry for very long and so an alien civilization observing at us would have to be very nearby, within 50 light years.”

While it’s unlikely that we could ever construct a Dyson sphere in our solar system, the idea is likely to remain in the popular science consciousness as we continue to search for extraterrestrial life. A key part of this search is to look for unexplained radiation emissions. Every time we detect such an emission near a star, someone is going to think of the Dyson sphere.