Scientists and artists have banded together to beam coded radio transmissions toward a star that has a potentially habitable planet, just 12.4 light-years from Earth.
Scientists have beamed a message toward the GJ 273 system where one of the two planets orbiting the red dwarf sun is thought to be within its habitable zone.
That means it may be capable of hosting life and, if it does, we might hear back in 2042.
The message is part of the 2018 Sonar festival in Spain, and includes 33 short pieces of music.
Festival director Richard Robles said: “Sonar Calling GJ273b arises from the innate human need to communicate and connect.
“It also attempts to find an answer to a question asked by civilisations throughout history: are we alone in the universe?
“Given the largely negative impact of humanity on our planet, perhaps this is the best time to reach out to hopefully superior extraterrestrial intelligence to solicit help and advice.”
Douglas Vakoch, president of Messaging Extraterrestrial Intelligence (METI) which sent the communication, told Space.com: “To me, the big success of the project will come if, 25 years from now, there’s someone who remembers to look [for a response].
“If we could accomplish that, that would be a radical shift of perspective.”
METI exists to “understand and communicate the societal implications and relevance of searching for life beyond Earth, even before detection of extraterrestrial life,” its website said.
Mr Vakoch dismissed suggestions that sending messages to potential alien races could be dangerous for humanity if one turns out to be aggressive.
He said: “It’s really hard to imagine a scenario in which a civilization around Luyten’s star could have the capacity to come to Earth and threaten us, and yet they’re not able to pick up our leakage radiation.”
Radio waves from Earth’s media networks have been travelling through space for decades.
But the fear of hypothetically hostile species from other stars is real for many scientists, including Stephen Hawking.
He has said that if we were to receive an extraterrestrial communication we should be “wary” of sending a reply.
Potential rival species could be vastly more powerful than humanity and contact could be like the meeting of Christopher Columbus and the Native Americans, the physicist has said – which “didn’t turn out so well”.
Even if it were benign, an interstellar civilisation could be so state-of-the-art it ”may not see us as any more valuable than we see bacteria”, he added last year.