Scientists Are Expanding the Search for Alien Signals to New Radio Frequencies

Scientists around the world have spent decades pointing radio telescopes at the sky, hoping to catch that one signal proving we’re not alone in the universe. But now researchers at SETI are asking: what if aliens have already reached out, and we accidentally left them hanging?

A new study led by University of Manchester researcher Louisa Mason and presented at the Royal Astronomical Society’s National Astronomy Meeting suggests it’s time to stop obsessing over one tiny slice of the radio spectrum and start checking as many of them as we can. Maybe there’s some vast alien civilization out there that’s been calling a phone we couldn’t hear ringing because we weren’t paying attention to it.

For quite some time now, SETI has focused on the “water hole,” a range of low-end radio frequencies between 1.42 and 1.66 GHz. Scientists figured any civilization that understands chemistry would recognize the frequencies emitted by hydrogen and hydroxyl (aka water) and use that part of the spectrum as the galaxy’s universal meeting place.

Scientists Say the Search for Alien Life Has Overlooked Key Radio Frequencies

Mason’s team thinks that method has limited our ability to hear what’s going on out there. The team is now searching much higher radio frequencies using archived data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

“The millimetre and submillimetre radio bands remain almost completely unexplored for SETI, so this is really about opening up a new area of parameter space to search,” Mason explained in a statement.

So far, they haven’t found any notable signatures, but the new approach opens the door to expansive parts of the radio spectrum that have up to this point been entirely unexplored. Who knows what kind of data is sitting there, and has been for decades?

So no alien voicemails have been detected just yet. But considering that we’ve spent decades listening to one frequency while several others have just been sitting there, potentially loaded with signals, scientists are beginning to wonder if the problem isn’t that nobody was talking but that we just never bothered flipping the channel to see if that’s where everyone was hanging out. There could be an alien party line out there, and we didn’t even know it.