Arecibo 1974 – Interstellar telegram or PR gimmick?

In this article I shall delve into whether Message Extra-Terrestrial Intelligence (METI) is a smart idea or not. I  seek to discuss and question whether the message broadcasted by Arecibo in 1974 was meant to reach out to another civilization, or was it just a PR gimmick?

Arecibo Observatory

The Arecibo Observatory, in Puerto Rico (USA) is a 305 m (1000 ft) radio telescope. It is the most powerful non military radio transmitter that mankind possesses. In 1974, it was used to broadcast a narrow-band signal ( ~ 10 MHz) at  2380 MHz towards the globular cluster Messier 13.  M 13 is a globular cluster in the constellation of Hercules and is at a distance of about 22000 light years. Globular clusters are some of the oldest objects in the known Universe and hence harbour a stable host environment for an intelligent life form to develop, say as opposed to a Star Forming Region.

The message contained 1679 (73 x 23) bits (0s and 1s) and was supposed to be a cheat sheet for alien civilizations to infer our presence and know more about humans and the fundamentals of our existence.  Further, the signal was barycentric corrected (motion of the Earth around the Sun) to ensure that the frequency received is not modulated due to this motion. It contained the following information  (taken from Wikipedia) –

  1. The numbers one (1) to ten (10) (white)
  2. The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA) (purple)
  3. The formulas for the sugars and bases in the nucleotides of DNA (green)
  4. The number of nucleotides in DNA, and a graphic of the double helix structure of DNA (white & blue)
  5. A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth (red, blue/white, & white respectively)
  6. A graphic of the Solar System indicating which of the planets the message is coming from (yellow)
  7. A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish (purple, white, & blue)

The Arecibo message represented pictorially  in a grid of 73 x 23 with colour added for clarity. Courtesy: Wikipedia

 

The intensity of the transmitted signal was such, that is would outshine the Sun by a factor of 10 billion (10^7). The intensity, narrow-band and the prime number factors should be enough to clue in the listener to the signal’s artificial origin. A fact that can be further confirmed by the contents of the signal.

Thus, it seems that the message was formulated and broadcasted to serve as an announcement of our place in the Universe. That being said, as has been clearly articulated at the end of NAIC STAFF, 1974: the target (why not M4, at one third the distance), the frequency (2380 MHz and not the waterhole frequency), and the duration of the message (only 169 seconds) clearly indicate that the message was not meant to initiate interstellar dialogue. Further they also mention that a serious attempt to initiate such a discourse should come from an international consensus of nations and not unilateral action. Rather I believe, that the broadcast was a technology demonstrator for the newly upgraded radio transmitter (funded by the National Science Foundation – NSF) . It was meant to garner public support towards funding scientific pursuit.

 

Considering that it was not really meant as an attempt to initiate interstellar dialogue, is it justified to classify it along with METI (Messaging to ET intelligence) ?