As of today, Friday 16th November 2018, it is 44 years since the Arecibo message was broadcast into the depths of space as a radio signal.

In 1974, this message was sent towards the M13 globular star cluster in the hope of reading extraterrestrial life and that they would be able to decipher it. The reason for choosing the M13 cluster is because though it is 25,000 light years away, it is relatively close to Earth, and a very large collection of stars available to view in the sky at that time.

It was broadcast into space via frequency modulated radio waves at a ceremony on the 16th of November 1974 to mark the remodeling of the Aricebo radio telescope in Puerto Rico.

The message consisted of 19.679 digits which is equal to approximately 210 bytes, and the total broadcast was under three minutes. They chose the number 1,679 because it is a semiprime number, the product of two primes. They were rectangularly arranged as 73 rows by 23 columns, and the inverse (23 by 73) produces an unintelligible instruction set. When translated from binary radio waves, the image above is formed, just in black and white. It has been coloured to make it easier for us to visualise and understand.

The message consisted of seven vital parts of our humanity and the lives we have led in the hopes the recipients can decode and understand what us humans are. As shown from the top to bottom:

  • The numbers one to ten in white.
  • The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up the basis of DNA, shown in purple.
  • The formulas for the sugars and bases in DNA nucleotides, shown in green.
  • In red, blue/white, and white respectively, there is a graphic figure of a human with the average physical height of a man and the human population of Earth at that time.
  • A depiction of the solar system which indicates which planet the transmission was sent from, shown in yellow
  • A graphic of the Arecibo radio telescope and the physical diameter of the transmitting antenna dish (purple, white, and blue)

Due to the minimum of a 50,000 years wait for transmission and response, this message is viewed as more of a show of a human technological advancement rather than a real attempt at communication. As the M13 cluster is in constant motion, the intended destination will be far from the point the transmission meets, but it will still be within the cluster.

Will this message one day bounce back with an alien message for us to decipher in return? Highly unlikely, yet in the space of 50,000 years, who can say? Maybe we will receive an external transmission of our own and spend years pouring over the details. Perhaps in billions of years, our message will be received somewhere we never intended to contact and they will reach back to us, unaware that we had been inevitably wiped out millions of years prior.

As of now, we are only showing off the progress we have made. But who knows - maybe one day we will send a message and adventitiously start an intergalactic war, or invite aliens to share our home. The Arecibo message is little more than a testament to our achievements. Nevertheless, I am content enough knowing a piece of our legacy will forever survive as the little radio transmission beaming through the cosmos.
 

Attached above: The Arecibo message, The M13 cluster.

Sources: https://en.wikipedia.org/wiki/Arecibo_message