A project known as Breakthrough Starshot hopes someday to use a powerful beam of energy to propel a tiny probe to another star. A recent study says that other civilizations might already be doing that, but on a much larger scale — and that we might have seen some of those beams.

Two researchers at Harvard considered the objects known as fast radio bursts. Astronomers have seen about a score of them, all in other galaxies. They’re intense outbursts of radio waves that last only a tiny fraction of a second. They could be powered by exploding stars, collapsing neutron stars, or some other exotic objects.

But the Harvard astronomers wondered if the bursts could have an artificial origin. And they concluded that it’s possible.

Their idea is that a civilization would build a starship propelled by a giant sail. A beam of radio waves would “push” the ship just as the wind pushes sailing vessels here on Earth. Occasionally, the radio beam would sweep past Earth — producing a radio burst.

If the radio beam were powered by solar energy, it would require a collector that’s about twice the diameter of Earth. Building and operating such a system wouldn’t be easy — but it’s within the realm of possibility. And the payoff could be big: it could propel a million-ton ship to a good fraction of the speed of light.

The researchers aren’t saying that fast radio bursts really are produced by other civilizations — only that it’s a possibility worth checking.

Script by Damond Benningfield