Earth is a noisy planet. Not just in a city-center noise pollution kind of way, but in more of a “we’re sending all kinds of signals out into space every day” kind of way. The world has gotten especially noisy since we learned how to transmit information over radio waves over 100 years ago.
According to a new study, some of the strongest of those radio signals have reached far-off stars. And apparently, if those stars happen to be home to extraterrestrial life that could respond to our ping, we could be hearing back as early as 2029.
It’s an incredibly long shot. “Our puny and infrequent transmissions are unlikely to yield a detection of humanity by extraterrestrials,” Jean-Luc Margot, a radio astronomer from UCLA, said in a Popular Science article. “The probability that another civilization resides in this tiny bubble is extraordinarily small unless there are millions of civilizations in the Milky Way.”
But it’s not impossible, and for some astronomers, “not impossible” is worth investigating. The team behind this recent study wanted to see if signals from NASA’s Deep Space Network, or DSN—the super-powered and super-focused radio array used to communicate with deep space missions like Voyager and New Horizons—could have run into any exoplanets by now that might host life.
The DSN isn’t the only thing sending out radio signals. We do that all the time by just listening to the radio or watching TV. But most of those waves aren’t targeted, and so they spread out into unreadability before they could ever reach an extraterrestrial life form. The DSN, on the other hand, was built specifically for long-distance communication, so there’s a much better shot that an alien civilization could read the information contained inside of that signal and realize it is worth responding to.
The team tracked the signals set out by the DSN and found a few stars that may have been hit by the radio waves. The nearest is a white dwarf star—a tiny, very dense star that can form when a larger star dies—located 27 light years away that may have been hit by a communication sent to a mission called Pioneer 10.
If there is a planet around that star (we have yet to spot any), and that planet responded as soon as they got our “message,” we could hear back as soon as 2029. Other messages meant for other deep spacecraft could be returned from different potential star systems in the 2030s.
The goal of this study was to provide potential targets for further analysis. In the search for extraterrestrial life, any kind of narrowing of the field is helpful, as searching the whole sky for transmissions is understandably difficult. After all, even if we spotted the right star, we could miss a shorter transmission by not having our receivers pointed the right way at the right time. If there’s life out there at all, it’s going to be hard to find and easy to miss, even with targets like this.
The curiosity and hope attached to the potential of finding alien life is pushing the field of astronomy forward every day. But it’s probably not worth buying a radio receiver in 2029.