Arecibo 74 pictogram, Chilbolton 2001 alien reply? by KerrAvon on Shapeways
In 1974 a message was sent into space from the Arecibo radio telescope in Puerto Rico.
It contained information relating to the human race: our binary number system,
DNA, a representation of how we look and population size, location in our solar
system and a description of the radio telescope that sent the message.
In 2001 a crop circle mysteriously appeared overnight in a field in Chilbolton,
Hampshire UK, next to a radio telescope.
It bore a striking resemblance to the original radio message, but with a
number of distinct differences... differences that suggest it might be a reply to
our original message from an alien species somewhere else in the universe.
https://info-quest.org/documents/The%20Chilbolton%20Crop%20Glyphs%20-%20A%20Message%20Finally%20Received%20-%20In%20Answer%20to%20Carl%20Sagan.htm
This single-sided pendant shows a pictogram of the 'alien reply' received in 2001.