The message was transmitted from the Arecibo Observatory on November 16th, 1974. It was deemed to be the first real attempt at Messaging Extraterrestrial Intelligence (METI).

Alien-Like Signal From 2023 Has Been Decoded. The Next Step Is To Figure Out What It Means SETI AIR artist Daniela De Paulis’ "A Sign in Space" project simulated receiving an extraterrestrial message ...

On the 50th anniversary of the “Arecibo message,” we present a reflection on humankind’s first attempt to send a transmission to intelligent life in the cosmos.

The search for extraterrestrial intelligence was a key part of the telescope's mission, and it broadcast Earth's first attempt to contact extraterrestrials — now known as the "Arecibo Message ...