Sónar wants to talk to aliens

Since last week a call to extraterrestrial intelligence crosses the void of space, towards the exoplanet Luyten b, at 12.5 light years. Sent by the Sónar festival to commemorate its 25th anniversary, the message contains 17 short pieces of electronic music, as well as a tutorial to reconstruct them and a pocket encyclopedia on the Earth and humanity.

Although nobody knows if there will be beings in Luyten b capable of receiving the signal, listening to the music and dancing to their sound, scientists have maximized the possibilities of its being deciphered. If in that remote world-close in cosmic terms-there is an intelligent civilization that has radio antennas, they should be able to understand the call. And if they decided to respond, their message could arrive in 25 years, coinciding with the 50th anniversary of Sónar.

“It is the first time that a message has been sent to a planet so close and that is suitable to house life,” says Ignasi Ribas, director of the Institute of Spatial Studies of Catalonia (IEEC), which has led the scientific conception of the project, nicknamed as Sónar Calling.

It is the first time that a message is sent to a planet so close and that is suitable to house life

Director of the IEEC and scientific director of Sónar Calling

Sónar has sent ten-second pieces produced by artists participating in the festival, in three transmissions between May 14 and 16, from a radar of the Eiscat association in Tromsø (Norway). The 17 musical creations broadcast last week are added to another 18 that were sent in October of last year. Of diverse nature, many are inspired by key aspects that define humanity. For example, Alva Noto sends his daughter’s heartbeat, captured in ultrasound. Ryoji Ikeda, a piece made with the 3,010 first decimal places of the number pi. And Kate Tempest, a composition inspired by the most relevant chemical elements for our species. All can be heard on the Sónar Calling page.

With three times the mass of our planet, astronomers think that Luyten b is a rocky world something different from Earth, although it has not yet been possible to observe directly. Orbit is known as Luyten’s star, a red dwarf older than the Sun, much smaller and less bright. Exoplanet Luyten b is located in the innermost region of the habitable zone of the system, which is the range of distances where an adequate temperature would be given for liquid water to exist; it is so close to its star that the years there last only the equivalent of 19 Earth days, explains Ignasi Ribas.

Luyten b is not the closest exoplanet to Earth. That title is held by Proxima b, at only 4.2 light years. However, it is the best candidate visible from Tromsø: the closest and most likely to be habitable, according to Ribas.

According to astronomers, it is not unreasonable to think that there could be living beings in Luyten b. “We do not know how likely it is that life emerges from nowhere in a place where the right conditions exist,” admits Ignasi Ribas. However, the astronomer says that “we know that, on Earth, wherever the minimum conditions for life are given, life ends up appearing”.

That this life is intelligent and that, in addition, be able to use the radio to receive and send communications is another story. “We are making many assumptions. That there is not only life but that he listens and responds to us, I see it very complicated, ” Jordi Portell, a researcher at the Institut de Ciències del Cosmos of the Universitat de Barcelona (ICCUB-IEEC), said in a telephone interview.

“It is very unlikely,” agrees Ignasi Ribas. “Life on Earth has a history of 3.6 billion years. Humans have been forming civilizations for 10,000 years. And only in the last hundred have we developed the communicative capacity “.

Even so, scientists have made every effort to ensure that, if there are intelligent extraterrestrials in Luyten b with at least our technological level, they will be able to understand the message of Sónar.

Life on Earth has a history of 3.6 billion years. Humans have been forming civilizations for 10,000 years. And only in the last hundred have we developed the communicative capacity “

Issued by pulses at two different radio frequencies, it is designed to differ as much as possible from a natural radio emission, which is not uncommon in the Universe. Each call begins with a Hello- ‘hola ‘ sign in English-: a pulse of one frequency, a pulse of the other; then two of each; three; five; seven; eleven. So until you reach 137. It is a sequence of prime numbers, a sign that it is an artificial emission. “There is no phenomenon in the Universe that is capable of generating a sequence of prime numbers in radiofrequency”, Jordi Portell reasons.

The pulses are also unusually slow, to make it easier to reconstruct the message between the background noise of the Universe.

To the signal Hello it is followed in each transmission by a tutorial encoded in binary code, with everything necessary so that the extraterrestrial potentials of Luyten b can decode and listen to the music. The tutorial includes an encyclopedia on the Earth and humanity in the form of an image, devised in the 90s by physicists Stéphane Dumas and Yvan Dutil. “First the size of the image is sent and then the data of its content”, explains Jordi Portell. If the two frequencies are translated as two different colors, when the pixels are reconstructed in order, a compendium with QR-like symbols appears that contains everything from the most basic mathematical operations to the human anatomy, including the composition of the DNA and the structure. of the Solar System, as well as the physical principles of sound.

If there is a response, “it would be one of the biggest news in the world that has been in recent centuries or even millennia”

If this signal reached Earth, we would be perfectly capable of capturing and deciphering it, remarked Portell and Ribas. However, it would be necessary to have a receiving antenna pointing to the place of origin of the call, or it would be overlooked. In these moments, it would be the most probable, since humanity does not have a systematic system of listening to the Universe. “We must trust that, if in Luyten b there is an intelligent and communicative civilization, they will have a project to listen to the closest stars, among which is the Sun,” says Ribas.


And what will happen if within 25 years we get an answer from Luyten b? “It would be the great answer. The answer of whether we are alone or not in the galaxy, “says Jordi Portell. “It would be one of the biggest news in the world that has been in recent centuries or even millennia,” he adds. “It is very difficult to predict, but it would be a global revolution, far beyond science”, says Ignasi Ribas. “A revolution of a caliber similar to what was there 400 years ago, when Copernicus showed that the Earth was not at the center of the Universe. It would be the cure of definitive humility, the demonstration that we are not the only intelligent civilization in the Universe, “Ribas concludes.