The Arecibo message is a interstellar radio message sent by the Arecibo radiotelescope carrying basic information about humanity and Earth that was sent to the globular cluster Messier 13 in November 16th, 1974 to conmemorate the remodelation of the radiotelescope. It was meant as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials.