Could Dyson Spheres Exist Around Other Stars?

Imagine a civilization so advanced that it doesn’t just rely on the fraction of starlight reaching its planet, but instead captures nearly all the energy emitted by its star. To us, that sounds like pure science fiction. Yet, the idea has been seriously considered by scientists. Back in the 1960s, physicist Freeman Dyson suggested that if intelligent civilizations exist elsewhere in the galaxy, one of the most efficient ways they could power themselves would be to build enormous structures around their stars. This concept became known as the Dyson Sphere.

What Exactly Is a Dyson Sphere?

Contrary to the popular image of a massive, solid shell enclosing a star like a cosmic light bulb, a Dyson Sphere is unlikely to be a continuous sphere. A rigid, complete shell would be gravitationally unstable and physically impossible with any material we know of. Instead, Dyson himself imagined something more realistic: a Dyson Swarm or Dyson Cloud—a vast collection of satellites, space stations, or solar collectors orbiting the star in different layers and trajectories.

These satellites would act like giant solar panels, absorbing starlight and transmitting energy wirelessly back to the civilization’s homeworld. In essence, a Dyson Swarm would function as a colossal power plant operating on a stellar scale. Rather than depending on the small slice of solar energy that naturally reaches a planet, a Type II civilization (on the Kardashev scale, which measures levels of energy use) could tap into all of its star’s output.

The Kardashev Scale: Measuring Civilizations

To better understand why Dyson Spheres are so fascinating, we need to look at the Kardashev Scale, proposed by Soviet astronomer Nikolai Kardashev in 1964. This scale classifies civilizations based on how much energy they can harness:

• Type I: A planetary civilization, capable of using all the energy available on its home planet. Humanity is not quite there yet—we’re roughly at 0.7 on the scale.
• Type II: A stellar civilization, able to capture the full energy output of its star. A Dyson Swarm would be the hallmark of such a civilization.
• Type III: A galactic civilization, capable of harnessing energy from an entire galaxy.

For us, the leap from Type I to Type II would be as revolutionary as fire was to our ancestors—except on a cosmic scale.

Could Dyson Spheres Exist Around Other Stars?

In theory, yes. If technological civilizations have arisen in the galaxy and survived long enough to expand their engineering capabilities, Dyson Spheres—or at least Dyson Swarms—are a natural next step. Different types of stars would offer different opportunities:

Red dwarf stars: These stars are small, stable, and can burn for trillions of years. That makes them excellent candidates for long-term Dyson Swarms.

Sun-like stars: These would provide enormous energy, but their lifespans are shorter than red dwarfs. Still, billions of years of usefulness is nothing to scoff at.

Giant stars: They output tremendous amounts of energy but live only a few million years. A civilization trying to build around them would need to work extremely quickly.

Multiple star systems: Imagine a swarm that captures energy from two or three stars at once. The possibilities would be staggering.

Searching the Skies for Dyson Spheres

Astronomers have already begun searching for signs of Dyson Swarms. If a star were surrounded by millions of solar collectors, its light would behave differently. Some of the visible light would be blocked, and the excess waste heat from the collectors would be re-radiated as infrared energy. In other words, a star with a Dyson Swarm might glow strangely in the infrared spectrum.

One famous case is KIC 8462852, better known as Tabby’s Star. In 2015, astronomers noticed it dimming in irregular and dramatic ways—up to 20% of its brightness. This sparked speculation that perhaps giant alien structures were orbiting it. Eventually, the mystery was attributed to large clouds of dust, but the event reminded us that searching for Dyson Spheres is not just science fiction. It’s an active area of astrophysical research.

The Enormous Challenges

Building even a partial Dyson Swarm would be an undertaking beyond anything humanity can currently imagine. The material required would be staggering—some estimates suggest disassembling an entire planet, perhaps something the size of Jupiter, to provide enough raw material for the millions or billions of orbiting collectors.

Then there’s the problem of stability and control. Each satellite would need to be kept in orbit without colliding with others. Energy transmission, whether via lasers, microwaves, or some other advanced technology, would need to be safe and efficient across astronomical distances.

Yet, for a civilization with millions of years of technological development, these problems might be no more insurmountable than building skyscrapers or power grids is for us today.

What It Means for Humanity

The concept of Dyson Spheres is more than just a thought experiment. If such structures exist elsewhere in the galaxy, they may be detectable with our telescopes. Finding one would be the ultimate confirmation that advanced civilizations are out there.

For us, the idea also serves as a long-term vision of what our species might achieve if we avoid self-destruction and continue to advance. Earth alone cannot sustain us forever. To truly thrive as a species, humanity may one day need to embrace stellar engineering on a grand scale.

Whether Dyson Spheres remain a distant dream or turn out to be a common reality among the stars, they challenge us to think bigger—far beyond our planet, and even beyond our solar system.