A group of scientists and artists just attempted to phone E.T.

The group beamed a message toward a red dwarf GJ 273, also known as Luyten’s star, on the slim chance that intelligent life lives on its small orbiting planet GJ 273b. As Mike Wall at Space.com reports, they sent the message in mid-October but did not reveal it to the public until yesterday.

METI sent their signal over the course of three days from the EISCAT 930 MHz transmitter outside the Arctic city of Tromsø in Norway. But don't expect a response anytime soon: It will take 12.5 years for it to reach the star system and the same amount of time for the return, "what's up?"

As Emma Grey Ellis at Wired explains, the message was crafted by a group called METI (Messaging Extraterrestrial Intelligence) that split from the SETI Institute (Search for Extraterrestrial Intelligence) in 2015. While SETI uses radiotelescopes and other tools to listen for signals that might be attributed to intelligent civilizations in space, METI’s founders want to take a more active approach to the search by beaming greetings and information from Earth to other potentially habitable exoplanets.

So what, exactly, do you say to aliens? METI partnered with the Spanish Sónar music festival and the Institute of Space Studies of Catalonia to create an introduction to music. According to Sónar, the introductory signal called the “Hello” message is designed to catch a receiver’s attention and to distinguish it from naturally occurring signals like pulsars. It is composed of small radio pulses that click on and off, representing prime numbers up to 137. The signal then sends a brief tutorial on 8-bit binary coding which will allow the listener to understand the rest of the message.

The message continues on with a tutorial that teaches the listener to translate the digital signal into sound. The introductory message was sent three times, each followed by several 10-second digital audio files composed by 33 musicians and sound artists. Even if the aliens can't physically reproduce the sounds or hear them, the team hopes they will enjoy the mathematical relationships of the notes.

“It's like creating a puzzle,” Mike Matessa, a cognitive scientist who helped develop METI's message tells Ellis. “We tried to make it as easy as possible, but it’s really challenging when you can’t refer to anything in your culture, only science.”

Douglas Vakoch, president of San Francisco-based METI tells Wall that this is the first of what he hopes will be many transmissions. In fact, the group is scheduled to send out a more complex musical message in April.

“[This message] is a prototype for what I think we would most likely need to do 100 times, or 1,000 times, or 1 million times,” he says. “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.”

Not everyone thinks letting the universe know about our existence is a great idea. Physicist Stephen Hawking, for one, has repeatedly warned that encountering extraterrestrials might not be the heart-warming E.T. experience we’ve imagined. As Hawking said in 2015:

“If you look at history, contact between humans and less intelligent organisms have often been disastrous from their point of view, and encounters between civilizations with advanced versus primitive technologies have gone badly for the less advanced. A civilization reading one of our messages could be billions of years ahead of us. If so, they will be vastly more powerful, and may not see us as any more valuable than we see bacteria.”

Then again, it’s possible the aliens already know we’re here, even without us beaming sound-art at them. Though they are increasingly faint with distance, our earliest radio broadcasts have traveled around 100 light years away, and television isn't too far behind.

So far, we haven’t heard anything back, but we're eagerly waiting for the first alien-produced episodes of “Law & Order: Crab Nebula.”