In January, we reported on a series of seven fast radio bursts (FRBs) that scientists were able to pinpoint to a specific galaxy more than three billion lightyears away. These bursts repeated at a set duration and lasted only one to five milliseconds each, perplexing astronomers and physicists alike and leading to a whole slew of theories as to their source, including the idea that they could be produced by alien life.

Other theories include supermassive black holes ejecting material back into space, supernova explosions greater in scale than any we’ve ever witnessed, and a list that continues to grow as our planet’s greatest thinkers and mathematicians compare notes, scratch their heads, and try their hardest not to jump to any conclusions that revolve around little green men.

However, a group of scientists and researchers at the Harvard-Smithsonian Center for Astrophysics (CfA) aren’t shying away from the possibility that these seemingly intelligent radio bursts could be produced by an alien civilization, and although that may sound crazy, nothing the human race has discovered in the nature of space can explain away these phenomena, leaving room to consider that perhaps these bursts aren’t naturally occurring at all.

“Fast radio bursts are exceedingly bright given their short duration and origin at great distances, and we haven’t identified a possible natural source with any confidence,” said Harvard professor Avi Loeb in a press release. “An artificial origin is worth contemplating and checking.”

In the popular video game franchise Mass Effect, your spacefaring character uses giant space installations known as “mass relays” to cover huge expanses of space instantaneously—like an artificially produced wormhole. According to the theory posited by Harvard’s team, these fast radio bursts might be the unintentional result of just such a giant device, but instead of opening wormholes, they believe these bursts might actually be utilized to propel spacefaring vessels with a variation on solar sail technology, not unlike the types being used in experiments by the Planetary Society and other space-oriented organizations on Earth.

Image from the Planetary Society’s recent LightSail test.

In the vacuum of space, a powerful light beam can actual propel a vessel by way of the energy transferred by light photons impacting a reflective surface. Current solar sail experiments originating on Earth utilize light from the sun to propel spaceships using an actual sail, but scientists have long considered the use of powerful lasers to propel a similar design. Shining the laser through the Earth’s atmosphere would dramatically reduce its range and transferrable energy, but a powerful laser installation on the moon could actually propel a craft rather well while it had line of sight with the ship.

Solar sail technology has its strengths and weaknesses. They tend to accelerate extremely slowly, making them poor choices for long-distance manned space travel. However, because they can accelerate continually in the vacuum of space, over time, a solar sail vessel can compound its speed and actually reach velocities unheard of by other spacecraft propulsion designs. A solar sail laser emitter that is so powerful it can be measured and recorded from three billion light years away could be so powerful that it actually propels ships to nearly the speed of light—allowing for a vessel to cross vast expanses of space at rates of speed humans can barely dream of.

According to Harvard’s team, such a power source would have to be planet-sized in order to produce bursts like the ones we’ve been receiving, and would likely be able to propel ships weighing in the millions of tons.