La Canada Flintridge (USA) Scientists have been discussing active attempts to contact extraterrestrials for years under the keyword METI (Messaging to Extraterrestrial Intelligence). Mankind’s first message to extraterrestrial life was sent into space back in 1974 with the Arecibo telescope. It will be more than 20,000 years before it reaches its destination, the globular cluster Messier 13. Meanwhile, various institutions have sent dozens of similar such messages, which the targets will receive in decades to centuries.
According to a publication on the preprint server arXiv, scientists from the Jet Propulsion Laboratory (JPL) have now worked out an update of the original Arecibo message. This new message contains significantly more information than the original that was sent 48 years ago.
As the team led by Jonathan H. Jiang from NASA’s Jet Propulsion Laboratory (JPL) explains in their technical article, the message known as the “Beacon in the Galaxy” (BITG) is based on the idea of the “Arecibo message” sent into space on November 16, 1974 with the Arecibo radio telescope.
The “Arecibo Message” is a binary encoded picture puzzle (i.e. using ones and zeros) and the business card of mankind (see Fig. left), which was sent in the direction of the globular cluster M13 in the constellation Hercules, 25,000 light years away not least because the astronomers saw a higher chance that the message could hit a world inhabited by an intelligent civilization due to the large number of stars in a small space. However, 48 years after the message was sent, it has only traveled 0.2% of the way to M13.
In order to recognize a logical picture (at least from a human point of view), a potential recipient would first have to break down the Arecibo message, which consists of 1679 bit units, into the prime factors of this number 23 and 73, and then split the units (bits) accordingly in a 23× grid Arrange 73 as pixels into a black and white image. In order to be able to recognize the objects contained in the message, a potential recipient would then have to recognize the empty lines as paragraphs and empty columns as lateral separations of neighboring objects.
In addition, the arrangement in the read/write direction is from left to right and line by line downwards. The writing direction to the left is equivalent, while a line sequence upwards would depict the figure of the human – on the vertically erected image – fallen, standing on his head. The arrangement in a 73×23 matrix, which is also possible, does not result in a meaningful representation – at least from a human point of view.
Correctly recognized and arranged, the resulting image can then – at least from a human point of view – identify the numbers from 1 to 10 (A), the number of protons in the chemical elements hydrogen, carbon, nitrogen, oxygen and phosphorus, as well as the four nucleotides as the building blocks of the Read DNA (B, C, D) and its double helix structure (E) as well as basic information about humanity (F, G, H), our solar system with the earth as the origin of the message (j) and finally the way the transmitting device itself (K, L).
The scientists from JPL also determined when and where the message will be sent, either by using the Allen Telescope Array or the Chinese giant telescope FAST, which was recently released for international researchers. The highest chance that the message will actually be received by extraterrestrials is when it reaches the center of the Milky Way. However, the message cannot be sent at the moment because the Arecibo radio telescope collapsed a year and a half ago. The other two radio telescopes must first be upgraded to send the message.
The researchers do not see a risk in this. They believe that a civilization technologically advanced enough to receive and decipher the message must also have recognized the value of cooperation and peace. In addition, humanity is constantly sending signals into the universe anyway, which could be used by a possible extraterrestrial civilization to discover the planet.
The new message will be broadcast using the world’s two largest radio telescopes, the FAST Telescope, also known as “Tianyan,” in southwest China and the SETI Institute’s Allen Telescope Array (ATA) in northern California.
The destination of the of the message should be a yet to be determined dense cluster of stars at a distance of 6,000 to 20,000 light years away, so much closer than the goal of the Arecibo message.
“Our message is simple but meaningful. Suppose we receive a response from intelligent aliens, we would assume that it is a response with similar information content,” conclude Jiang and his colleagues. “Perhaps such an answer would describe the mathematical system of these extraterrestrials in binary form, which may be based on a different system. In theory, such an answer could also contain basic information about the local biosphere chemistry and the appearance of the extraterrestrials – although likely, they would not necessarily have to be based on carbon after all. In such a scenario, the answer would be a direct analogy to the BITG message and would provide a common language base for further communication and answer many of our questions even before a dialogue.”
So far, however, there is still a small problem: Both FAST and ATA are currently only able to receive radio signals and can not transmit them. “However, that should change soon with the coming updates of the systems,” the BITG authors are confident and hope that they may be able to send their message on time for the 50th anniversary of the original Arecibo message.