The ‘Arecibo Message’ was broadcast from Earth in 1974, towards the globular star cluster M13.
During the dedication of the Arecibo Observatory – still one of the largest single radio telescopes in the world – a string of 1’s and 0’s representing the diagram was sent.
This attempt at extraterrestrial communication was mostly ceremonial – humanity regularly broadcasts radio and television signals out into space accidentally. Even were this message received, M13 (22,200–25,000 light-years away from Earth) is so far away we would have to wait almost 50,000 years to hear an answer.
The featured message gives a few simple facts about humanity and its knowledge: from left to right are numbers from one to ten, atoms including hydrogen and carbon, some interesting molecules, DNA, a human with description, basics of our Solar System, and basics of the sending telescope.