Arecibo reply

In 1974 the Arecibo message was broadcast into space. In 2001 hoaxers made a reply “from aliens” in a field next to another observatory.

Johannes Rössel, CC BY-SA 3.0, via Wikimedia Commons

In 1974, to mark the refurbishment of the Arecibo radio telescope, a radio message was broadcast into outer space. The message was sent to the Messier 13 star cluster, 25,000 light years away. In the forty-seven years since then, it has travelled 0.188% of the way there. By the time the message arrives, the star cluster itself may have moved on… but the point of the message was never to actually contact aliens. Instead, the message showed off advances in human technology. It was good press, in other words.

The Arecibo radio telescope itself collapsed last year. So much for human technology and good press:

The message sent in 1974 contained a series of encoded symbols. Properly ordered, they describe numbers (as a primer to interpret the rest of the message), the elements and chemical compounds that make up DNA, the structure of DNA, a little graphic of a human, a map of the solar system, and a picture of the radio telescope itself.

Aliens have yet to send a reply. In 2001, though, anonymous crop circle enthusiasts created their own response to the Arecibo message. They impressed it into a field next to another radio telescope, in Hampshire in the United Kingdom.

The new message is very similar to the Arecibo message, but the hoaxers added a few small changes. For starters, the DNA is a different shape, and the references to carbon (as in carbon-based lifeforms) were replaced with silicon. The solar system map is completely different and implies three habited planets. The hoaxers switched the picture of the telescope for an abstract squiggle: the same squiggle appeared in a different crop circle one year earlier. But the best and most arresting change was in the human figure. The Arecibo reply instead shows an alien – bulging head, giant eyes, and all.