Are you there, aliens? It’s us, Earth. Astronomers have sent a radio message to a neighbouring star system – one of the closest known to contain a potentially habitable planet – and it’s nearby enough that we could receive a reply in less than 25 years.

“I think that’s an unlikely outcome, but it would be a welcome outcome,” said , president of Messaging Extraterrestrial Intelligence (METI) International. METI is an offshoot of the more familiar SETI – the Search for Extra-Terrestrial Intelligence.

The target star is GJ 273, also known as Luyten’s star, a red dwarf in the northern constellation of Canis Minor, just 12 light years away. In March of this year it was discovered to have two planets. One of them, known as GJ 273b, orbits within the star’s “habitable zone” and could potentially harbor liquid water, and perhaps life.

Telling time

This missive to the stars was sent on the anniversary of the “Arecibo message,” a radio transmission beamed toward a distant star cluster in 1974 from the Arecibo radio telescope in Puerto Rico. The Arecibo message contained information on the planets of our solar system, the structure of DNA, a cartoon-like picture of what a human being looks like, and other basic information about the earth and its inhabitants.

This new message – beamed from an antenna in Norway over roughly eight hours over a three-day period in October – is simpler and may be more readily understood, Vakoch says.

It begins with information about counting, arithmetic, geometry, and trigonometry, and includes a description of the radio waves that carry the message, as well as a tutorial on clocks and timekeeping, to see if any potential inhabitants of GJ 273b have an understanding of time similar to our own.

Inviting our own doom?

The idea of intentionally sending messages into space has always been controversial, even within the SETI community. One issue is that it’s far from clear who should speak for humankind. Another concern is the potential danger of reaching out to extraterrestrials.

Physicist Stephen Hawking and others have warned against the possible repercussions of encountering an alien civilization – noting that such a civilization will almost certainly be far older and far more technologically advanced than our own.

“Ninety-eight percent of astronomers and SETI researchers, including myself, think that METI is potentially dangerous, and not a good idea,” says , a SETI researcher at the University of California at Berkeley. “It’s like shouting in a forest before you know if there are tigers, lions, and bears or other dangerous animals there.”

Read more: We still haven’t heard from aliens – here’s why we might never

Harking back to the far-off days when he was a grad student, physicist Stephen Hawking recalls how physicists bristled at the idea of a big bang, with its echoes of the biblical Genesis story.

“One would have to appeal to religion – an act of God – to determine how the universe started off,” is how he describes the objectors’ attitude. In those days, the very question of whether the universe actually had a beginning was a controversial one, he adds.

Hawking, now aged 68, was speaking on Sunday at the prestigious in Waterloo, Ontario, as he begins a six-week stint there.

Disappointingly to some, his presentation, titled “To boldly go: My life in physics”, made no mention of popular topics such as time travel or aliens that he has weighed in on in the past.

Bubbling universe

Instead he took the opportunity to look back at the topics in physics and cosmology that have grabbed his attention over the years, from the nature of black holes to the problem of how the universe began.

The question of the big bang was settled in the mid-1960s with the discovery of the cosmic microwave background radiation – the “echo” of the big bang that showed that the universe did have a beginning, he said.

But Hawking reminded the audience that physicists are still trying to deduce the precise mechanism of the universe’s explosive birth, and whether there is just one universe or a vast “multiverse” spawned by a multitude of bangs.

It is possible, Hawking said, that universes spring into being “like the formation of bubbles and steam in boiling water”. A few of these baby universes reach a critical size, and go on to form galaxies, stars “and maybe beings like us”, he added.

Key ingredients

Less mysterious, he said, is the matter of fostering the kind of innovative thinking that leads to scientific breakthroughs. “The recipe is simple: Put willing people together in an inspiring and creative intellectual environment where they are encouraged to pursue ambitious and timely research.”

Hawking spoke of Germany in the 1920s, when the foundations of quantum mechanics were developed, and again of Cambridge, UK, in the 1960s, when the framework of modern cosmology was established. He then courteously likened the environment at Perimeter to these powerhouses of innovation. “It seems to me, the same ingredients are being assembled here in Waterloo,” he said.

Expecting the Perimeter Institute to deliver insights on this scale is clearly a tall order. Even the institute’s director, physicist , admitted that assembling brilliant minds in one place is just one element; luck is still a factor.

What is perhaps a more certain result of Hawking’s time in Canada is that scientists there – particularly young ones – will be inspired by his presence. “To try out your idea on somebody as insightful as Stephen can be extremely valuable,” Turok told żěè¶ĚĘÓƵ.

Hawking holds a Distinguished Research Chair at the Perimeter Institute, and is expected to spend several weeks there each summer. “I am hoping, and expecting, great things to happen here,” he said.