On Nov. 16th, 1974, the most powerful signal ever beamed into space was broadcast from the Arecibo Radio Telescope in Peurto Rico. Designed by famed SETI researcher Frank Drake (creator of the Drake Equation) and famed science communicator Carl Sagan, the broadcast was intended to demonstrate humanity’s level of technological achievement. Forty-eight years later, the Arecibo Message remains the most well-known attempt to Message Extraterrestrial Intelligence (METI).

To mark the occasion, an international team made of researchers led by Jonathan H. Jiang of NASA’s Jet Propulsion Laboratory has come up with a new signal! Known as The Beacon in the Galaxy (BITG) message, this updated signal combines aspects of the original Arecibo Message with every METI attempt made to date – like the Pioneer Plaques, the Voyager Golden Records, and the Evpatoria Transmission Messages (ETMs).

Jiang was joined by researchers from the SETI Institute, the Virginia Polytechnic Institute and State University, the University of Cambridge, the Hanze University of Applied Sciences, the Chevron Energy Technology Company, the School of Physics and Technology at Wuhan University, Beijing Normal University, and the University of California at Los Angeles. The paper that describes their findings recently appeared online.

A team of astronomers from UCLA searched for “technosignatures” in the Kepler field data. Credit and Copyright: Danielle Futselaar

The Original Signal

Audio representation of the Arecibo message sent to space in 1974. Credit: NAIC/UCF

The transmission was part of a ceremony that marked the end of a three-year upgrade to the Arecibo’s 305m (1000 ft) Radio Telescope. This included aluminum panels on the giant spherical reflector antenna to improve accuracy, a high-power S-band radar transmitter, and modifications to the superstructure to accommodate S-band frequencies. The emission was equivalent to a 20 trillion watt broadcast and would be detectable about anywhere in the galaxy if the receiving antenna was similar in size to Arecibo’s.

The message’s destination was M13, a globular star cluster located near the edge of the Milky Way Galaxy (about 22,180 light-years away). This cluster was believed to be a good candidate for finding intelligent civilizations since it is estimated to be 11.66 billion years old and contains approximately three-hundred thousand stars. Drake and Sagan decided to use prime numbers since they believed it would make the message easier for an alien civilization to translate.

“The Arecibo Message was the first carefully designed message into space, encoded in radio waves, hoping to get in touch with alien civilizations,” said Jiang to Universe Today via email. “It pioneered Earth’s first attempt to contact aliens.

The broadcast consisted of a 1,679-binary digit pictogram (210 bytes), which is the product of two prime numbers, arranged rectangularly into 73 lines of 23 characters per line (also prime numbers). The ones and zeroes were simulated by shifting the frequency at a rate of 10 bits per second, and the total broadcast lasted less than three minutes. They conveyed a series of scientific, geographical, biological, and astronomical information in different colors. These included:

A counting scheme of 1 to 10 (white)The atomic numbers for hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up DNA (purple)The chemical formula of the four purines and pyrimidine bases that make up DNA (green)An image of the DNA double helix and ab estimate of the number of nucleotides (blue and white, respectively)A stick-figure of a human being (red) our average dimensions (blue/white), and the human population of Earth (white)A depiction of the Solar System, indicating that the message is coming from the third planet (yellow)A schematic of the Arecibo Observatory and its dimensions (purple/white and blue)

Before and Since

Numerous METI attempts have been made since the beginning of the Space Age. The first radio signal deliberately broadcast to space was the Morse Message, which was sent from the Evpatoria Planetary Radar (EPR) in Ukraine in 1962. This