Why we might be searching for aliens the wrong way

Before one edition of LEAP we interviewed Bill Diamond (President and CEO at the SETI Institute). We’ve kept a close eye on the research coming from SETI ever since – and recently, the institute’s work has been pushing scientists to rethink the way they search for extraterrestrial intelligence. 

For over 60 years, that search has been guided by the idea that if another civilisation exists, it might be transmitting a radio signal powerful enough for us to detect. 

Since astronomer Frank Drake's Project Ozma became the first modern SETI experiment in 1960, researchers have searched the skies for narrowband radio signals that are so precise that they're unlikely to occur naturally. If we found one, it could be evidence of technology rather than physics. 

Rethinking the search

But what if we've been listening too narrowly?

A recent study from the SETI Institute suggests that turbulent plasma surrounding distant stars could broaden narrowband radio signals before they even leave their home stellar systems. Rather than arriving as the clean, tightly focused signals that searches have traditionally looked for, they could be spread across a wider range of frequencies – making them much harder to recognise using existing search techniques. 

To put it another way, the problem may not be that extraterrestrial signals don't exist. It could be that some of them no longer look like the signals we expected to find.

The implications are significant. Around 75% of the stars in the Milky Way are M-dwarfs – exactly the kind of stellar environments where the researchers predict this signal broadening could be strongest. If the hypothesis proves correct, some of the galaxy's most promising targets may also be the places where radio signals are hardest to detect. 

If we put aliens aside for a moment, this is a really valuable reminder that scientific progress isn’t always driven by better tech. Sometimes it comes from questioning the assumptions behind the search. 

Asking better questions

In our 2024 interview with Diamond, he reflected on exactly that philosophy: 

"I have really grown to appreciate that science is not about providing answers, but rather, it's about asking questions – and asking the right questions! And…each new answer we obtain simply raises ten new questions."

It’s the mindset that has shaped the SETI Institute since its founding in 1984. Today, more than 100 scientists explore everything from exoplanets and planetary habitability to microbiology, astronomy and even animal communication – partly to answer whether we're alone in the universe, but also to better understand what intelligence and communication look like in the first place. 

Looking beyond the stars

COSMIC is one of the most ambitious SETI programmes. Running on the National Radio Astronomy Observatory's Very Large Array in New Mexico, the project continuously analyses the telescope's full field of view while it carries out other astronomical observations, allowing researchers to search enormous volumes of data for potential technosignatures.

Diamond described COSMIC as:

"Perhaps the most comprehensive SETI research project ever undertaken."

Yet some of the institute's most intriguing research isn't pointed towards the stars at all. Diamond also highlighted work led by astronomer Laurance Doyle, who studies humpback whale vocalisations alongside marine biologists. The goal is to understand whether there are universal mathematical principles behind communication itself.

As Diamond explained:

"By applying Information Theory to these whale communications, the research teams hope to determine if there are universal rules that apply to information transfer that would then presumably apply to any and all communications – including those of alien civilisations."

Searching for extraterrestrial intelligence, it turns out, sometimes begins by listening more carefully to life on Earth.

More than a search for aliens

Possibly the biggest misconception about SETI is that the institution’s scientists spend all their time waiting for a dramatic message from another civilisation. 

In reality, modern SETI is as much about improving our understanding of astronomy, signal processing, information theory and the nature of intelligence itself.

Whether researchers ultimately detect a technosignature or not, every refinement in how they search expands our understanding of the universe – and of ourselves.

As Diamond told us:

"The search for life beyond Earth teaches us a great deal about life and habitability on our own planet and it helps us understand what it means to be human."