The Arecibo message is a 1974 interstellar radio message carrying basic information about humanity and Earth sent to globular star cluster M13 in the hope that extraterrestrial intelligence might receive and decipher it. The message was broadcast into space a single time via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo radio telescope in Puerto Rico on 16 November 1974. The message was aimed at the current location of M13 some 25,000 light years away because M13 was a large and close collection of stars that was available in the sky at the time and place of the ceremony. The message consisted of 1,679 binary digits, approximately 210 bytes, transmitted at a frequency of 2,380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 450 kW. The “ones” and “zeros” were transmitted by frequency shifting at the rate of 10 bits per second. The total broadcast was less than three minutes.
The number 1,679 was chosen because it is a semiprime (the product of two prime numbers), to be arranged rectangularly as 73 rows by 23 columns. The alternative arrangement, 23 rows by 73 columns, produces jumbled nonsense (as do all other X/Y formats). The message forms the image shown on the right, or its inverse, when translated into graphics, characters, and spaces.
Dr. Frank Drake, then at Cornell University and creator of the Drake equation, wrote the message with help from Carl Sagan, among others. The message consists of seven parts that encode the following (from the top down):
- The numbers one (1) to ten (10) (white)
- The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA) (purple)
- The formulas for the sugars and bases in the nucleotides of DNA (green)
- The number of nucleotides in DNA, and a graphic of the double helix structure of DNA (white & blue)
- 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)
- A graphic of the Solar System indicating which of the planets the message is coming from (yellow)
- A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish (purple, white, & blue)
Since it will take nearly 25,000 years for the message to reach its intended destination (and an additional 25,000 years for any reply), the Arecibo message is viewed as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials. In fact, the core of M13, to which the message was aimed, will no longer be in that location when the message arrives. However, as the proper motion of M13 is small, the message will still arrive near the center of the cluster. According to the Cornell News press release of November 12, 1999, the real purpose of the message was not to make contact but to demonstrate the capabilities of newly installed equipment.
Two Canadian astronomers published a study that claims an anomaly in the pulsing of a group of stars is possibly evidence of an alien civilization. It’s easy to be skeptical of any such proposals but the scientists really do consider an extraterrestrial involvement as one of the potential explanations to what they’ve observed.
The scientists Ermanno Borra and Eric Trottier from the Université Laval in Quebec analyzed modulations in 2.5 million stars from the Sloan Digital Sky Survey project and concluded that 234 of them exhibited strange behavior. In fact, the stars seemed to be signaling, with the conceivable explanation that it’s aliens trying to make contact. This theory was bolstered by the conclusion that the 234 signals perfectly matched the shape of an extraterrestrial intelligence (ETI) signal, predicted by Borra’s previous study.
Also working in their favor is the sheer specificity of the sample – 234 stars out of 2.5 million emit a very specific signal, something that fits into previous ETI models.
“We find that the detected signals have exactly the shape of an [extraterrestrial intelligence] signal predicted in the previous publication and are therefore in agreement with this hypothesis,” the scientists write in their paper. “The fact that they are only found in a very small fraction of stars within a narrow spectral range centered near the spectral type of the sun is also in agreement with the ETI hypothesis.”
The scientists do acknowledge that other explanations are possible for the weird signals, like “rotational transitions in molecules” or “rapid pulsations”or maybe even the unusual chemistry of a small group of galactic halo stars.
But you know it’s aliens.
Also thinking that this is worth a closer look is the Breakthrough Listen Initiative, a $100 million program aimed at looking for intelligent life in space. It’s headlined by Stephen Hawking and Mark Zuckerberg. The group announced that it will look into the findings of the Canadian astronomers further, but would like to see some independent proof.
In its statement, Breakthrough Listen summarized its goals with respect to the strange signals:
“Extraordinary claims require extraordinary evidence. It is too early to unequivocally attribute these purported signals to the activities of extraterrestrial civilizations.”
“Internationally agreed-upon protocols for searches for evidence of advanced life beyond Earth (SETI) require candidates to be confirmed by independent groups using their own telescopes, and for all natural explanations to be exhausted before invoking extraterrestrial agents as an explanation.”
The study is published in the Solar and Stellar Astrophysics journal.
Here is the announcement of the objectives for the Breakthrough Initiatives by the Russian billionaire Yuri Milner and Stephen Hawking: