Arecibo Message (1974)

A 3-minute radio shout into the cosmic void/Events & Phenomena

On November 16, 1974, the Arecibo Observatory transmitted a 1,679-bit message toward the globular star cluster M13, about 25,000 light-years away. The message, designed by Frank Drake and Carl Sagan, encoded information about DNA, humans, the solar system, and the Arecibo telescope itself. Even traveling at the speed of light, the message will not arrive for another 25,000 years, and any reply would take another 25,000 years to get back.