Case file · Cosmic event
The Arecibo message
On 16 November 1974 the Arecibo radio telescope beamed a 1,679-bit picture message toward the globular cluster M13, the most famous deliberate signal humans have sent to the stars.
1974 CE · 18.34, -66.75 · status: official
The account
Written by Frank Drake with Carl Sagan and others, it encoded numbers, DNA chemistry, a human figure, the solar system and the telescope itself. It was a demonstration for the dish's upgrade rather than a serious attempt at contact; M13 is about 25,000 light-years away. Arecibo was later used for SETI searches until the dish collapsed in December 2020.