The #NewAreciboMessage is an effort by astronomers to enlist students and teachers to design a message to be sent to help contact possible aliens:
The main goal of this activity is to educate the youth on Radio Astronomy techniques and Exoplanetary cutting-edge science, presenting the uniqueness of the Arecibo Observatory capability and raising the awareness of the possible risks involved on messaging unknown earthlings (through social media) or extraterrestrial civilizations (through radio waves).
Students, from kindergarten to undergraduate courses, are welcome to join the New Arecibo Message (NAM) global challenge! From elementary-, middle-, high-schools, universities and similar Education organizations.
In addition to finding details at its website, you can read all about it at Vox, Astronomers are asking kids to help them contact aliens.
I don’t usually share videos from RT American, the news site funded by the Russian government, because often their work is pretty biased. However, this particular clip on this challenge seems pretty straight and useful: