Irish scientists on team scanning for signs of intelligent alien life

Using the Irish LOFAR (Low Frequency Array) telescope and its counterpart in Onsala, Sweden, the team — led by Professor Evan Keane, Associate Professor of Radio Astronomy in Trinity’s School of Physics, and Head of the Irish LOFAR Telescope — plans to monitor millions of star systems.

Scientists have been searching for extraterrestrial radio signals for more than 60 years. Many of these have been carried out using single observatories which limits the ability to identify signals from the haze of terrestrial interference on Earth. Much of the effort has focused on frequencies above 1 GHz because the single-dish telescopes employed operate at these frequencies.

Now, a new collaboration led by Trinity College Dublin, with the Breakthrough Listen team and Onsala Space Observatory in Sweden, is perfecting a multi-site, multi-telescope technique that allows them to search at much lower frequencies of 110 – 190 MHz.

There is a cutting-edge astrophysics observing facility in Birr Castle, County Offaly — this facility connects Ireland to the International LOFAR Telescope.

The Breakthrough Listen programme is the most comprehensive search for technologically advanced extraterrestrial life, developing dedicated instruments at the Irish and Swedish LOFAR stations. Using multiple sites means we are less likely to get a 'false positive' signal — such signals arise due to interference from many human sources on Earth.

The team has just published details of their method and their ongoing search in the Astronomical Journal. They have already scanned 1.6 million star systems flagged as interesting targets by the Gaia and TESS space missions, run by ESA and NASA respectively. So far these searches have drawn a blank.

But they point out that the search has only just begun...

Professor Keane said: “In the last 50 years evidence has steadily mounted that the constituents and conditions necessary for life are relatively common in the Universe, which begs one of life’s greatest unanswered questions: are we really alone? To some people the ‘Search for Extra-terrestrial Intelligence, or SETI’ might seem like something from a movie, but it has been a scientific pursuit for decades, and for a host of very good reasons. With this project we are basing our search on the common assumption that civilisations elsewhere in the universe may employ similar technologies to those developed on Earth. As a result radio frequencies are a logical domain for conducting SETI surveys due to the widespread use of telecommunications and radar and our access to next-gen radio telescopes offers a great chance for a deep dive into the universe.”

Owen Johnson, PhD Candidate in Trinity’s School of Physics, is the first author of the journal article, and the first Irish person to ever undertake a PhD on the topic of SETI. He added: “What makes surveys like this one truly captivating is the fact that we're pushing these telescopes to their absolute limits, directing them towards substantial portions of the sky. As a result, we have the exciting possibility of discovering all sorts of wild and wondrous phenomena during this process and if we're very fortunate, even encountering our cosmic neighbours."

Johnson, age 23 and from Wicklow, acknowledged that any discovery of extraterrestrial life might not be as shocking to many people as it might once have been: "Now that we know there are more than 5,000 other planets beyond our solar system and the more we realise how big the universe is, the more people consider it likely there will be some sort of life detected."

And if something is really 'out there' there's a whole post-detection protocol to be followed. This is established by the International Academy of Astronautics and means that data has to be properly verified. 

"There would have to be years of follow-up observations — no announcement would be based on just one observation when it could turn out to be a problem with an instrument or anything," explains Johnson. 

But he noted that any life detected is very unlikely to be big-headed green humanoids and may range from microbial life to something beyond our comprehension altogether: "There may be biosignatures such as signs of microbial life or techno signatures from artificially manufactured devices which would imply an intelligent civilisation."

“LOFAR is soon to undergo a staged series of upgrades across all stations in the array across Europe, which will allow an even broader SETI at ranges of 15 - 240 MHz. We have billions of star systems to explore and will be relying on some machine learning techniques to sift through the immense volume of data. That in itself is interesting — it would be fairly ironic if humankind discovered alien life by using artificial intelligence," Johnson pointed out.

For now, though it might be worth keeping the wisdom of science and science fiction writer, Arthur C Clarke in mind: “I'm sure the universe is full of intelligent life. It's just been too intelligent to come here.”