The Arecibo Message
Once upon a time, humanity decided to send out a radio message into space attempting to demonstrate humanity's technological achievements. Although the message itself was only compromised of 1,679 bits, the location humanity wanted to sent that message to was an astonishing 25,000 lightyears away. The message can be translated into a very underwhelming graphic. Think of something so basic it almost can't even be considered as pixel art.
This took place back in 1974 and the message was known as the Arecibo message.