Alien Dyson spheres may indeed exist, but under special conditions

Dyson spheres—hypothetical mega-structures advanced civilizations might use to enclose a star and harness its energy—are catastrophically unstable. However, an engineer now claims a solution: using two stars.

In the 1960s, physicist Freeman Dyson proposed that an advanced society could disassemble a planet to build a spherical shell around a star, capturing vast energy and living space.

Dyson calculated that a shell made from a planet with the mass of Jupiter could completely enclose the sun at roughly the orbit of Earth. But gravity inside a hollow shell cancels out, meaning the star could crash into it, destroying the structure.

In a January 29 paper in Monthly Notices of the Royal Astronomical Society, engineer Colin McInnes proposed a theoretical fix: a binary star system, reports livescience.com.

He searched for stable points where a Dyson sphere could avoid collapse. One arrangement—encasing both stars—was only mildly stable. Another, where the sphere orbited independently, lacked energy-capturing benefits.

However, McInnes found a stable, useful configuration in systems where one star is much smaller.

The Dyson sphere can enclose the smaller of the two stars. The motion of that smaller star acts like a gravitational anchor, keeping the Dyson sphere in motion with the same orbit around the larger star, preventing a catastrophic collision.

Key limitations exist: the smaller star must be under one-tenth the mass of the larger, and the sphere must be extremely lightweight.

Otherwise, gravitational interactions destabilize the system. Additionally, engineering challenges—like structural stress—remain unaddressed.

While humans are unlikely to build Dyson spheres, this research aids the search for alien civilizations. We shouldn’t look for them around solitary stars.

Instead, scientists could target large stars with dim, infrared companions—potential signs of a Dyson sphere around a smaller star.