Sónar Calling GJ273b

Sónar, Barcelona's music, creativity and technology festival celebrates its 25th anniversary. Since its inception in 1994, Sónar has remained true to its name and has continued to track the most innovative, radical and engaging music on the planet. To celebrate its 25th year, Sónar has decided to reverse its role, switching from radar to antenna. This is how the Sonar Calling project GJ273b was born in which a quarter of a century of musical exploration will be condensed and sent it into space, specifically to the exoplanet Luyten Star b, with the objective of making first human contact with an extra-terrestrial intelligence.

Sónar leads this artistic-scientific experiment in collaboration with two pioneering institutions in the detection of extra-terrestrial life: the IEEC (Catalonia Institute of Space Studies) and METI International (Messaging Extra-terrestrial Intelligence). The project involves 35 artists linked to the festival, from diverse musical origins and discourses. The IEEC is a research institute that studies all areas of space science, including the planet Earth, the Solar System, exoplanets, stellar physics, astroparticle physics, and cosmology. The IEEC conducts projects on the discovery of habitable planets and has supported the search for extra-terrestrial intelligence (SETI, SETI@home and BOINC) for more than a decade and hosts the website SETI.cat. The project’s second partner is METI International, the ground breaking organization in the design of messages capable of being understood by extra-terrestrial civilizations. Founded in 2017, it carries out scientific research and educational programs on the sending of Intelligent Extra-terrestrial Messages (METI) and the Search for Extra-terrestrial Intelligence (SETI).

Contact with an extra-terrestrial intelligence has been an object of interest and fascination for decades. In the 70's, the first SETI named projects (search for extra-terrestrial intelligence) were carried out, which included the use of the Arecibo radio telescope (Puerto Rico) both to detect possible emissions of civilizations in other star systems and for the sending of radio messages, and materials in space probes, to interplanetary space. Much energy has been focused on listening to different stars to detect signs of alien intelligence. Thus far there have been no positive results, apart from a single signal, the so-called “Wow!”, which has yet to be explained. Since 1974, transmissions have been sent to well known brightly shining stars, as well as to stars with giant exoplanets. There has been no success to date. In recent years many exoplanets have been discovered orbiting stars similar to the Sun, with some of them seeming to meet the requirements for habitable worlds. It is therefore the perfect time to make a first attempt at communication with these planet’s hypothetical civilizations.

For the second transmission in May 2018 the project counts with the collaboration of the Canadian astrophysicist Dr. Yvan Dutil who back in 1999 together with his colleague Stéphane Dumas defined a small “dictionary” of symbols or concepts, each described with an image of a few pixels. The tutorial section of our message presents the different concepts little by little, as if we were teaching a baby to talk.

From a scientific point of view, this experiment is unique as it directs a transmission to a specific nearby exoplanet that appears to offer the necessary conditions to house life. The encoding, cadence and power used to send the message is also unique and significantly increases the chances of it being received and understood by a non-terrestrial intelligence. The design of the message by IEEC and METI is propaedeutic: each section of the message contains the necessary information to decode the next section. The message contains both basic information about humanity and several pieces of music. From a musical standpoint, this project is innovative due to the active participation of a significant number of musicians of renown who have created special musical pieces to be sent to Luyten's Star b.

The transmission is directed at the Luyten Star, also known as GJ 273. Luyten's Star is located in the Canis Minor constellation at a distance of 12.4 light years from Earth. It is a much cooler star than our Sun with a temperature of around 3,000ºC (compared to the Sun’s 5,500ºC) and is therefore more reddish in colour. We estimate a mass and a radius that is approximately one third of our sun’s. The star is not visible without a telescope. It was named after a Dutch-American astronomer, Willem Jacob Luyten, who measured its movement (compared to other distant stars). In 2017 he announced the discovery of two orbiting planets. One of them, with a mass almost three times greater than the Earth, is located in the innermost edge of the habitable zone of the star. Its year is equivalent to 19 days on our own planet. It is called the Luyten Star b. This planet also has a nearby smaller neighbour with a mass 30% more than that of our own planet and whose year lasts around 5 days, it is called Luyten’s Star c. We do not know if Luyten’s Star b has water, nor if retains an atmosphere that makes it habitable. But presently we also have no reason to think otherwise. If it did, it would be a world with oceans like ours, perhaps hotter, with a sky lit by a star larger in appearance than the sun, shining with a reddish glow.