Arecibo Message

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.

Several searches for extraterrestrial intelligence are currently underway, including one where you can use your own home computer.

source APOD