The question of whether intelligent life exists elsewhere in the universe has intrigued humanity for centuries.
As human technological advancement progresses, the quest for answers to this question has become increasingly urgent.
Although we have yet to discover any solid evidence of extraterrestrial intelligence, several scientific, philosophical, and technological hypotheses suggest that the possibility is worth serious consideration.
The first effort to “connect” with extraterrestrial civilizations began in the 1960s.
Under the framework of the Search for Extraterrestrial Intelligence (SETI) project, researchers used radio telescopes to “scan” the sky.
Their goal was to search for unusual signals that could indicate the presence of an unknown civilization.
In addition to radio signals, scientists also consider indicators of advanced technology, such as hypothetical megastructures surrounding planets and stars (known as “Dyson spheres”), pollutants in atmospheres, or unusual energy emissions…
According to them, detecting such signs would provide compelling evidence of intelligent life beyond Earth.
Moreover, researchers have also attempted to “send messages” to extraterrestrial intelligent life, believing that if such life exists somewhere in the universe, it might respond positively to our outreach.
1. Morse Code
Among the hundreds of communication methods, Morse code is the first key term mentioned.
Morse code is the most basic protocol used in telecommunications to encode text characters, creating a standardized sequence of two different time intervals for signals.
The first Morse code message sent into space consisted of three words: MIR (meaning both “peace” and “world” in Russian), LENIN, and USSR.
This message was sent by the USSR under Lenin to the planet Venus in 1962, transmitted in two parts.
The message “MIR” was transmitted on November 19, 1962, and the second message, including LENIN and USSR, was sent on November 24, 1962.
Both signals reflected off Venus’s surface and returned to Earth in about four and a half minutes, with no response.
However, the message continues to travel through space towards the constellation Libra.
2. Visual Messages
If Morse code was the chosen method of communication with extraterrestrials by the USSR, then visual messages were the approach taken by American scientists.
They believed that if aliens could not understand our language or used a different method, images would still be a fundamental element for recognition and information comprehension.
For this reason, NASA attached gold-plated aluminum panels to the outside of the Pioneer 10 and Pioneer 11 spacecraft, depicting a naked man and woman along with several symbols designed to provide information about the spacecraft’s origins.
These included a diagram of the hydrogen conversion process, the most abundant element in the universe; a star map with the Sun at the center, displaying the relative distances of 14 stars and their binary cycle.
Additionally, a sketch of our Solar System was presented on the aluminum panels, with a long arrow pointing to Earth as the planet that launched the spacecraft.
Pioneer 10 was launched in 1972. It flew past Jupiter in 1973, Saturn’s orbit in 1976, Uranus’s orbit in 1979, and Neptune’s orbit in 1983.
The last successful contact with Pioneer 10 occurred in 2002, over two decades ago, when it was 12 billion kilometers from Earth. Currently, Pioneer is heading towards the star Aldebaran (65 light-years away) in the constellation Taurus.
Pioneer 11 was launched in 1973. It flew past Jupiter in 1974 and Saturn in 1979.
In contrast to the fate of its “brother” Pioneer 10, the spacecraft lost all power and ceased operations in 1995. It is currently heading towards the constellation Aquila.
3. Highly Informative Messages
The Arecibo Message was transmitted into space from the Arecibo Observatory in Puerto Rico on November 16, 1974.
This message was directed towards the location of the M13 star cluster, approximately 25,000 light-years from Earth. It was not merely a greeting or simple words.
Assuming extraterrestrials could decode it accurately, the 1,679 bits of data contained in the message would reveal numbers counting from 1 to 10, the atomic numbers of the basic elements that make up DNA, information about the structure of the DNA double helix, the size of an adult human, a graphical representation of humans, and the Earth’s population at that time (around 4 billion people).
Additionally, the message included images of the Solar System, a depiction of the Arecibo radio telescope, and the size of the dish transmitting the signal.
Subsequent messages also carried a wealth of information, such as signals sent from Yevpatoria, Ukraine, in 1999 and 2003, which included special symbols forming an alphabet, operators, units of measurement, names of planets, chemical elements, physical concepts, and biological concepts…
A message from Earth (AMFE) was transmitted on October 9, 2008, to Gliese 581c, an exoplanet orbiting the Gliese 581 system at a distance of 20.5 light-years, containing 501 messages selected through a competition on the social media site Bebo.
More than half a million people, including celebrities and politicians, participated in the AMFE project, aiming to create a rich array of information sent as messages. However, some argue that sending too much irrelevant information may not solve anything.
4. Audio Recordings
In addition to visual messages and radio signals, we have also sent audio recordings, hoping that some civilizations might actually “hear” them and understand.
When the Voyager 1 and 2 spacecraft were launched in 1977, each carried identical audio recordings. These were selected to describe the diversity of life and culture on Earth.
The recordings included greetings in 55 ancient and modern languages, other human sounds such as footsteps and laughter, musical works by Bach, Mozart, Beethoven…
Instructions on how to use and play the recordings were also depicted with drawings and special symbols.
To date, Voyager 1 has passed through the orbit of Pluto in 1990 and left the Solar System in 2004.
In about 40,000 years, these two spacecraft will approach two separate stars, approximately 1.8 light-years apart.
Specifically, Voyager 1 will reach the star Gliese 445 in the constellation Camelopardalis, while Voyager 2 will approach the star Ross 248 in the constellation Andromeda.
5. Rare Signal Response
Among the dozens of signals transmitted, we have yet to be fortunate enough to discover any civilization that responds. Even the instances of feedback are exceedingly rare.
One of those rare occurrences happened on August 15, 1977, when the Big Ear radio telescope of Ohio State University (USA) detected a strong signal from the direction of the Sagittarius constellation.
However, contrary to expectations, this was merely a natural signal originating from hydrogen, the most abundant element in the universe.
While we have not found any signs of a civilization within 50 light-years, life may still exist out there.
They are simply waiting for our “call.” Or this might just be an assumption we make to explain our ongoing efforts.
Until then, the big questions will remain unanswered. Are there extraterrestrials? Are they friendly? How do they communicate with us?
Or more importantly, as physicist Stephen Hawking once mentioned in his book, is it wise for us to contact extraterrestrial beings?
