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0 / 30 Fotos
A bold call
- The Arecibo Message was sent into the cosmos on November 16, 1974, from the Arecibo Observatory in Puerto Rico. It was nothing more than a brief stream of binary data, delivered as a long-distance “hello” to unknown cosmic neighbors.
© Getty Images
1 / 30 Fotos
Birthplace
- At the time that the message was sent, the Arecibo Observatory was the most sensitive tool for exploring the universe. It took three years to construct, opening its doors in 1963.
© Getty Images
2 / 30 Fotos
An impressive construction
- The gigantic bowl-shaped radio dish of the observatory was built in a natural sinkhole. The steel platform suspended above it weighed an astonishing 900 US tons (816 metric tons).
© Shutterstock
3 / 30 Fotos
A technological leap
- The Arecibo Message marked the inauguration of the telescope’s powerful new transmission capabilities, which allowed it to broadcast signals with unprecedented reach and strength. In fact, it was able to transmit signals with a power twenty times greater than the combined output of all the power plants on Earth at that time.
© Shutterstock
4 / 30 Fotos
Vision of connection
- Astronomer Frank Drake (renowned for the Drake Equation, which is used to estimate the number of extraterrestrial civilizations in the Milky Way Galaxy) designed the message that would be sent. His innovative approach framed humanity’s attempt to communicate with aliens in the simplest term: the binary code.
© Getty Images
5 / 30 Fotos
Ones and zeros
- Binary code, which consists of nothing more than ones and zeros, was used in the Arecibo Message because it is a simple and universal system that can be understood by any being capable of basic mathematical reasoning.
© Shutterstock
6 / 30 Fotos
A team effort
- Graduate students at Cornell University helped refine Drake’s design, contributing key elements to the message that would inevitably be sent.
© Shutterstock
7 / 30 Fotos
Format
- The final message contained 1,679 bits (short for “binary digits”) arranged in a grid of 73 rows by 23 columns. The message consists of seven parts that encode various pieces of information about humanity.
© Public Domain
8 / 30 Fotos
1. Numbers
- The first section of the Arecibo Message lists the numbers from one to 10 in binary. This serves as a foundation for the message, demonstrating to aliens the concept of counting and binary representation, which should be intelligible to other advanced beings.
© Public Domain
9 / 30 Fotos
2. DNA elements
- This section uses the numbers one, six, seven, eight, and 15, which are the atomic numbers of hydrogen, carbon, nitrogen, oxygen, and phosphorus. These elements are fundamental to life on Earth and form the building blocks of DNA.
© Public Domain
10 / 30 Fotos
3. Nucleotides
- The third part outlines the chemical formulas of 12 organic molecules (or “nucleotides”) that make up DNA. All of Earth's life forms are constructed using the same genetic framework, and this section shows what that framework looks like using atomic numbers of elements.
© Public Domain
11 / 30 Fotos
4. Double helix
- This section graphically represents the iconic double-helix structure of DNA, with lines connecting its components. It also includes the number 4,294,967,296 in binary, which represents the approximate number of base pairs in human DNA.
© Public Domain
12 / 30 Fotos
5. Humanity
- A human figure stands at the center of this section, accompanied by a vertical line on the left to indicate the average height of humans (about 5'9", or 175 cm, encoded using the wavelength of the transmission). On the right, the Earth's human population (approximately 4.3 billion in 1974) is encoded in binary.
© Public Domain
13 / 30 Fotos
6. Planets
- The sixth part of the message is a graphical representation of the solar system. The Sun and the nine planets (including Pluto at the time) are depicted, with Earth shifted up to show the origin of the message.
© Public Domain
14 / 30 Fotos
7. Telescope
- The final section displays the Arecibo radio telescope as the transmission source. Its shape is depicted in binary alongside its approximate diameter of 1,004 ft (306 meters). The letter “M” was put there to show that the curved line is a concave mirror.
© Public Domain
15 / 30 Fotos
Cosmic humility
- The message, which was broadcast for three minutes at a frequency of 2380 megahertz, wasn’t about expecting a reply. Not only was it humanity’s way of saying, “We’re here,” but it also demonstrated our potential for interstellar communication.
© Shutterstock
16 / 30 Fotos
A long distance
- The encoded transmission was sent in the direction of Messier 13, a massive star cluster in the Hercules constellation some 25,000 light-years away.
© Shutterstock
17 / 30 Fotos
Non-responsive
- Given Messier 13’s distance from Earth, any reply could take about 50,000 years. The experiment was less about conversation and more about imagining the possibilities of contact across space and time.
© Shutterstock
18 / 30 Fotos
The dark side
- Critics have warned that broadcasting Earth’s location could invite danger. Criticisms such as these have been known to draw on speculative theories like the Dark Forest, where civilizations hide to avoid attracting hostile forces.
© Shutterstock
19 / 30 Fotos
A cautionary tale
- Today, international protocols like those from the SETI Institute urge broader discussions before sending interstellar messages, placing emphasis on inclusivity and ethical responsibility in crafting future communications.
© Getty Images
20 / 30 Fotos
Competing signals from Earth
- While the Arecibo Message was deliberate, Earth continuously leaks signals into space via TV broadcasts and radio waves. These emissions make our existence detectable to any advanced alien listeners.
© Shutterstock
21 / 30 Fotos
Transformed by discovery
- Since the message was sent, over 5,000 exoplanets have been identified in the cosmos, including potentially habitable ones. Our understanding of where life might exist in the cosmos has significantly deepened.
© Shutterstock
22 / 30 Fotos
Estimating first contact
- Scientists estimate that four stars will receive the Arecibo Message within its first 500 years of travel, starting with a star known as Gaia DR3 1328057940089589376, located approximately 395 light-years away.
© Getty Images
23 / 30 Fotos
A new message
- In 2018, Arecibo scientists held a competition to create an updated transmission. Undergraduate students from Puerto Rico’s University of Mayaguez drafted a more detailed transmission, which included a galactic map, physical constants, and schematic updates.
© Getty Images
24 / 30 Fotos
Honoring the original
- The new design echoed the 1974 version, sticking to binary code and schematic simplicity while modernizing details like excluding Pluto and adding key cosmic landmarks like Saturn’s rings. Interestingly, the biological data of life on Earth was omitted.
© Public Domain
25 / 30 Fotos
A closer target
- Teegarden’s Star, a mere 12.5 light-years away, was selected as the destination for the updated message. With potentially habitable planets, a reply from this system could arrive within 25 years.
© Shutterstock
26 / 30 Fotos
Collapse
- In 2020, the Arecibo Observatory collapsed due to structural damage caused by Hurricane Maria. Its loss marked the end of an era for radio astronomy and interstellar communication.
© Getty Images
27 / 30 Fotos
Preserving a scientific legacy
- For Puerto Rican scientists and students, Arecibo was a gateway to the stars, and its collapse disrupted a scientific cornerstone of the community. However, plans are underway to transform Arecibo’s site into an educational center so that its contributions to astronomy and science will inspire future generations.
© Getty Images
28 / 30 Fotos
An enduring hope
- The legacy of Arecibo and its message is truly an apt reflection of the deep yearning that humanity has in understanding our place in the cosmos. As technology, creativity, and imagination continue to thrive on Earth, we can only hope that our cosmic neighbors will be willing to say hello in return. Sources: (National Geographic) (Scientific American) (History.com)
© Shutterstock
29 / 30 Fotos
© Public Domain
0 / 30 Fotos
A bold call
- The Arecibo Message was sent into the cosmos on November 16, 1974, from the Arecibo Observatory in Puerto Rico. It was nothing more than a brief stream of binary data, delivered as a long-distance “hello” to unknown cosmic neighbors.
© Getty Images
1 / 30 Fotos
Birthplace
- At the time that the message was sent, the Arecibo Observatory was the most sensitive tool for exploring the universe. It took three years to construct, opening its doors in 1963.
© Getty Images
2 / 30 Fotos
An impressive construction
- The gigantic bowl-shaped radio dish of the observatory was built in a natural sinkhole. The steel platform suspended above it weighed an astonishing 900 US tons (816 metric tons).
© Shutterstock
3 / 30 Fotos
A technological leap
- The Arecibo Message marked the inauguration of the telescope’s powerful new transmission capabilities, which allowed it to broadcast signals with unprecedented reach and strength. In fact, it was able to transmit signals with a power twenty times greater than the combined output of all the power plants on Earth at that time.
© Shutterstock
4 / 30 Fotos
Vision of connection
- Astronomer Frank Drake (renowned for the Drake Equation, which is used to estimate the number of extraterrestrial civilizations in the Milky Way Galaxy) designed the message that would be sent. His innovative approach framed humanity’s attempt to communicate with aliens in the simplest term: the binary code.
© Getty Images
5 / 30 Fotos
Ones and zeros
- Binary code, which consists of nothing more than ones and zeros, was used in the Arecibo Message because it is a simple and universal system that can be understood by any being capable of basic mathematical reasoning.
© Shutterstock
6 / 30 Fotos
A team effort
- Graduate students at Cornell University helped refine Drake’s design, contributing key elements to the message that would inevitably be sent.
© Shutterstock
7 / 30 Fotos
Format
- The final message contained 1,679 bits (short for “binary digits”) arranged in a grid of 73 rows by 23 columns. The message consists of seven parts that encode various pieces of information about humanity.
© Public Domain
8 / 30 Fotos
1. Numbers
- The first section of the Arecibo Message lists the numbers from one to 10 in binary. This serves as a foundation for the message, demonstrating to aliens the concept of counting and binary representation, which should be intelligible to other advanced beings.
© Public Domain
9 / 30 Fotos
2. DNA elements
- This section uses the numbers one, six, seven, eight, and 15, which are the atomic numbers of hydrogen, carbon, nitrogen, oxygen, and phosphorus. These elements are fundamental to life on Earth and form the building blocks of DNA.
© Public Domain
10 / 30 Fotos
3. Nucleotides
- The third part outlines the chemical formulas of 12 organic molecules (or “nucleotides”) that make up DNA. All of Earth's life forms are constructed using the same genetic framework, and this section shows what that framework looks like using atomic numbers of elements.
© Public Domain
11 / 30 Fotos
4. Double helix
- This section graphically represents the iconic double-helix structure of DNA, with lines connecting its components. It also includes the number 4,294,967,296 in binary, which represents the approximate number of base pairs in human DNA.
© Public Domain
12 / 30 Fotos
5. Humanity
- A human figure stands at the center of this section, accompanied by a vertical line on the left to indicate the average height of humans (about 5'9", or 175 cm, encoded using the wavelength of the transmission). On the right, the Earth's human population (approximately 4.3 billion in 1974) is encoded in binary.
© Public Domain
13 / 30 Fotos
6. Planets
- The sixth part of the message is a graphical representation of the solar system. The Sun and the nine planets (including Pluto at the time) are depicted, with Earth shifted up to show the origin of the message.
© Public Domain
14 / 30 Fotos
7. Telescope
- The final section displays the Arecibo radio telescope as the transmission source. Its shape is depicted in binary alongside its approximate diameter of 1,004 ft (306 meters). The letter “M” was put there to show that the curved line is a concave mirror.
© Public Domain
15 / 30 Fotos
Cosmic humility
- The message, which was broadcast for three minutes at a frequency of 2380 megahertz, wasn’t about expecting a reply. Not only was it humanity’s way of saying, “We’re here,” but it also demonstrated our potential for interstellar communication.
© Shutterstock
16 / 30 Fotos
A long distance
- The encoded transmission was sent in the direction of Messier 13, a massive star cluster in the Hercules constellation some 25,000 light-years away.
© Shutterstock
17 / 30 Fotos
Non-responsive
- Given Messier 13’s distance from Earth, any reply could take about 50,000 years. The experiment was less about conversation and more about imagining the possibilities of contact across space and time.
© Shutterstock
18 / 30 Fotos
The dark side
- Critics have warned that broadcasting Earth’s location could invite danger. Criticisms such as these have been known to draw on speculative theories like the Dark Forest, where civilizations hide to avoid attracting hostile forces.
© Shutterstock
19 / 30 Fotos
A cautionary tale
- Today, international protocols like those from the SETI Institute urge broader discussions before sending interstellar messages, placing emphasis on inclusivity and ethical responsibility in crafting future communications.
© Getty Images
20 / 30 Fotos
Competing signals from Earth
- While the Arecibo Message was deliberate, Earth continuously leaks signals into space via TV broadcasts and radio waves. These emissions make our existence detectable to any advanced alien listeners.
© Shutterstock
21 / 30 Fotos
Transformed by discovery
- Since the message was sent, over 5,000 exoplanets have been identified in the cosmos, including potentially habitable ones. Our understanding of where life might exist in the cosmos has significantly deepened.
© Shutterstock
22 / 30 Fotos
Estimating first contact
- Scientists estimate that four stars will receive the Arecibo Message within its first 500 years of travel, starting with a star known as Gaia DR3 1328057940089589376, located approximately 395 light-years away.
© Getty Images
23 / 30 Fotos
A new message
- In 2018, Arecibo scientists held a competition to create an updated transmission. Undergraduate students from Puerto Rico’s University of Mayaguez drafted a more detailed transmission, which included a galactic map, physical constants, and schematic updates.
© Getty Images
24 / 30 Fotos
Honoring the original
- The new design echoed the 1974 version, sticking to binary code and schematic simplicity while modernizing details like excluding Pluto and adding key cosmic landmarks like Saturn’s rings. Interestingly, the biological data of life on Earth was omitted.
© Public Domain
25 / 30 Fotos
A closer target
- Teegarden’s Star, a mere 12.5 light-years away, was selected as the destination for the updated message. With potentially habitable planets, a reply from this system could arrive within 25 years.
© Shutterstock
26 / 30 Fotos
Collapse
- In 2020, the Arecibo Observatory collapsed due to structural damage caused by Hurricane Maria. Its loss marked the end of an era for radio astronomy and interstellar communication.
© Getty Images
27 / 30 Fotos
Preserving a scientific legacy
- For Puerto Rican scientists and students, Arecibo was a gateway to the stars, and its collapse disrupted a scientific cornerstone of the community. However, plans are underway to transform Arecibo’s site into an educational center so that its contributions to astronomy and science will inspire future generations.
© Getty Images
28 / 30 Fotos
An enduring hope
- The legacy of Arecibo and its message is truly an apt reflection of the deep yearning that humanity has in understanding our place in the cosmos. As technology, creativity, and imagination continue to thrive on Earth, we can only hope that our cosmic neighbors will be willing to say hello in return. Sources: (National Geographic) (Scientific American) (History.com)
© Shutterstock
29 / 30 Fotos
Behind the message sent to aliens 50 years ago
A call for connection sent far away from home
© Public Domain
In November 1974, humanity reached out to the cosmos with its first deliberate interstellar message. The encoded transmission, crafted with care, curiosity, and a touch of boldness, has yet to reach its intended destination. Yet, this groundbreaking act is a true symbol of our yearning to connect with intelligent alien life. Decades later, the Arecibo Message remains a cornerstone of humanity’s search for life in the cosmos.
Where did scientists send this message? What exactly did they put inside it? And can we expect to receive a response? Click through this gallery to find out.
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