's "white dot" is not fiction.
1977, two Voyager detectors - " Voyager 2 " and "Voyager 1" were launched from Cape Canaveral, Florida on August 20 and September 5 respectively, starting their legendary mission, which has been 45 years since then.
, the two spacecraft used the rare bead-continuous phenomenon and gravitational slingshot effect of Jupiter , Saturn , Uranus and Neptune every 176 years, and achieved visits to multiple planets in one go. As of now, "Voyager 1" is about 23.3 billion kilometers away from the earth, and "Voyager 2" is about 19.3 billion kilometers away from the earth. They will not approach the next planet within 40,000 years.
Although the two detectors are still working, the nuclear battery it currently carries can only work until around 2025, when people will lose contact with them forever.
On February 14, 1990, when Voyager 1 completed its exploration mission toward Neptune and continued to march towards the edge of the solar system, NASA issued an instruction to instruct it to take the first "family portrait" of the solar system before it permanently turned off the camera. In this "family portrait", our earth is just a 0.12-pixel dim blue dot hanging in the vast dark space. The stripes scattered by the sunlight lay the background, one of which happened to pass through the earth.
is also the photo that inspired the famous American astronomer Dr. Carl Edward Sagan and wrote the book "Pale Blue Dot: A Vision of the Human Future in Space". Today, Uncle Ku led everyone into the book and learned the achievements and style of "Voyager".
article | Carl Edward Sagan
translation | Ye Shihui Huang Yiqin
edited | Tian Shuo Outlook Think Tank
This article is an excerpt from Outlook Think Tank book, excerpted from "Dark Blue Dot" (published by People's Posts and Telecommunications Press in November 2014). The original text has been deleted and does not represent the views of Outlook Think Tank.
1 "Voyager" victory
"Voyager 1" and "Voyager 2" are two spacecraft that opens the solar system for mankind and opens new ways for future generations . Before they were launched in August and September 1977, we knew almost nothing about the planetary part of the solar system. In the 12 years after its launch, they provided us with the first batch of detailed information and close-ups of many new planets, and in the past, some of these new planets looked blurry round surfaces, some were only spots of light, and some of them had never even thought about their existence. These two spacecraft are still sending back a lot of information.
On December 10, 2018, NASA released a schematic diagram of the locations of "Voyager 1" and "Voyager 2".
These spacecraft let us understand the wonders of other worlds, the uniqueness and vulnerability of our world, and the origin and end of the universe. They bring us closer to most areas of the solar system—in terms of breadth of range and numerous numbers. It is these spacecraft that first detects the astral bodies that may become the home of our future descendants.
Currently, the power of the launch vehicle of the United States is not very powerful enough, and it is difficult to deliver such a spacecraft to Jupiter or further in a few years with the advancement of the rocket alone. But we are smart (and lucky), and there is another way: we can fly (like " Galileo " did) to the vicinity of a celestial body and let its gravity push us to the next celestial body, which is called gravity support. It's kind of like playing a carousel, grabbing a post above it when it turns around, which will speed you up and go some new direction. The acceleration of the
spacecraft is offset by the deceleration of the planet's orbit around the sun. But because the planets have much larger mass compared to spacecraft, the planets have almost not slowed down at all. In turn, Jupiter's movement around the sun slows down. How many of this is there? Five billion years from now, when our sun becomes an expanding red giant , Jupiter will move closer toward the sun by 1 millimeter than when the Voyager had not yet flew over it in the late 20th century.
"Voyager 2" uses the rare "planetary beads" astronomical phenomenon. It flies near Jupiter, accelerates and sails towards Saturn, then goes from Saturn to Uranus, from Uranus to Neptune, and then flies to the stars through Neptune. But you can't do it any time you want: the last chance of this celestial "continuous bead" game was when Thomas Jefferson was president. At that time, people were in a period of detection only on horseback, in canoe and on sailboats (at that time, steamboats were new technologies that were about to emerge).
[Note: Jefferson was the third president of the United States (1743-1826) and was re-elected for two terms from 1801 to 1809. 】
On each of the four giant planets, Jupiter, Saturn, Uranus and Neptune, the two or one of the above spacecraft studied the planet itself and its ring belt and the satellite . In 1979, they were attacked by the captured charged particle at a dose of 1,000 times the radiation dose to kill people. In the full encirclement of this radiation, they discovered several rings of the largest planet, some active volcanoes seen for the first time outside of Earth, and the underground seas that might exist on a planet without air. There are many amazing discoveries in addition. In 1980 and 1981, they survived the ice storm attack and found not a few, but thousands of new rings. They examine frozen satellites that had mysteriously melted relatively recently, and a large star body that might have a sea of liquid carbon-hydrogen compounds (a cloud of organic matter floating above).
[Note: The large astral body refers to the Titan, the largest moon of Saturn, and it has been confirmed that there is a liquid hydrocarbon lake on Titan . 】
On January 25, 1986, "Voyager 2" entered the Uranus system and reported a series of strange events. The rendezvous lasted only a few hours, but the information sent back to Earth caused a revolution in our understanding of this blue-green planet. On August 25, 1989, Voyager 2 skipped through the Neptune system and observed the ever-changing patterns of clouds under the faint illumination of the distant sun; and a quirky satellite, above which the wind in the amazingly thin atmosphere blew the coils of organic particles. Until 1992, it had already flown over the outermost planets known, and the two Voyager spacecraft also received radio radiation, which can be thought of as the place where solar wind gave way to stellar wind .
[Note: "Voyager 1" has flew away from the top of the solar wind layer]
Voyager 1.
Because we live on Earth, we have to stare at distant stars through an atmospheric ocean that deforms images. Most of the ultraviolet light, infrared light, and radio waves they emit cannot penetrate our atmosphere. It is easy to understand why our spacecraft have revolutionized the study of the solar system: we ascend to a completely transparent vacuum space, approach our targets like the Voyager, fly past them, or orbit them, and even land on their surfaces.
Before Voyager 2 was about to meet with the Uranus system, the mission designers had set a final maneuver, that is, to briefly ignite the propulsion system on the spacecraft to correct the spacecraft's position and make it pass along the scheduled route. But the reality is that this kind of route correction is no longer necessary. After flying 5 billion kilometers along an arcuate path, the spacecraft is still within 200 kilometers of its designed trajectory. Its accuracy is roughly equivalent to throwing a needle and allowing it to pass through the needle hole 50 kilometers away; or shooting in Washington and hitting a cow in the eye of Dallas .
The precious information contained in the planet is transmitted back to Earth by radio.But the earth is too far away after all. When the radio telescope on the ground collects Neptune's signal, its receiving power is only 10-16 watts. Compared with the power of an ordinary desk lamp, this weak signal is like the ratio of the diameter of an atom to the distance between the earth and the moon. wants to receive such a signal, it is like hearing the "footsteps" of an amoeba .
Voyager No. 2.
Each "Voyager" weighs about one ton and can fill a cottage. each requires about 400 watts of power—much less energy than an average American home—provided by a generator that converts radioactive plutonium into electricity.
If the current passes through the spacecraft, a strong magnetic field will be generated, which is enough to interfere with the sensitive instruments that measure the interplanetary magnetic field. Therefore, the magnetometer is placed at the end of a long hanging rod, far away from the current that causes adverse effects. This boom with other protruding parts makes the Voyager spacecraft look a bit like an porcupine . The camera, infrared and ultraviolet spectrometer, and an instrument called a photographic polarization measuring instrument are placed on a scanning platform that rotates around the bracket according to the instructions to align various devices with the observed star body. As long as the antenna is pointing correctly, the spacecraft will definitely know where the earth is, so information can be transmitted back. It also needs to know the location of the sun and at least one bright star so that it can determine its orientation in three-dimensional space and correctly point to any star passing nearby. If you can't point the camera at the right time, the spacecraft can't teleport back images from billions of kilometers away well.
2 is not perfect
The cost of each spacecraft is roughly as expensive as a strategic bomber . However, unlike the bomber , once the "Voyager" is launched, it cannot be reclaimed for repair. Therefore, the computers and electronic instruments on the spacecraft are designed to be very cumbersome. Many critical components, including the main radio receiver , have at least one spare part. Whenever a Voyager spacecraft fails, the computer uses branches of the tree logic program that handles accidents to develop an appropriate set of action programs. If this does not solve the problem, the spacecraft will send a telegram to go home for help.
The Jet Propulsion Laboratory Control Room of the National Aeronautics and Space Administration in Pasadena, which not only monitors the Voyager 1's voyage, but also plays a navigation role.
spacecraft is getting farther and farther away from the earth, and the radio travel time becomes longer. When Voyager is at the distance of Neptune, this time is close to 11 hours. Therefore, once an emergency occurs, the spacecraft needs to know how to put itself in a safe standby state waiting for the earth's command. As the spacecraft ages, its mechanical components and computer systems will fail more and more; however, until now, no serious memory loss and some automatic devices have occurred.
This is not to say that the Voyager spacecraft is perfect. The extremely nervous accident in the serious threat detection task did occur. each time a group of engineers—some people participated in the Voyager program from the beginning—formed a special team to "handle" the problem. They study relevant scientific and technological data and use their original experience with failed components. They use the same Voyager spacecraft equipment that has never been launched to perform experiments, or even make many failed components to conduct some statistical research on their failure methods.
In April 1978, nearly eight months after launch, the spacecraft was approaching asteroid belt , when a ground command was missed - a man-made error - that caused the computer on Voyager 2 to be connected to its backup machine without connecting to the main radio receiver. When the next time the ground sends instructions to the spacecraft, the backup receiver fails to lock the signal from the earth because a component called the tracking ring capacitor fails.After Voyager 2 was completely lost to contact for 7 days, its fault alert software suddenly ordered the backup receiver to disconnect and let the main receiver turn on. However, the main receiver mysteriously failed after a moment and could no longer hear its sound (to this day, no one knows why).
In order to complete the mission, the computer on the spacecraft foolishly insists on using the failed main receiver. is just like that, thanks to a series of unfortunate mistakes made by man and computers, the spacecraft is now in real danger. No one can think of a way to get "Voyager 2" to restore the use of backup receivers. But even if this is done, because the capacitor fails, the backup receiver cannot receive instructions from the earth. Many designers have worried that everything will be done.
But after a week of indifferent and unresponsive to Earth's instructions, the spacecraft finally received instructions for automatic conversion between two receivers . That week, Jet Propulsion Laboratory engineers designed an innovative instruction frequency control program to ensure that damaged backup receivers can also understand the main commands.
engineers are now at least initially able to resume contact with the spacecraft. Unfortunately, the backup receiver is now becoming very unstable, and it is extremely sensitive to the heat emitted when various components of the spacecraft are powered on and off. In the following months, engineers at the Jet Propulsion Laboratory thoroughly figured out the heat impact of most spacecraft operating modes through some experiments designed and conducted: what factors would hinder and which would allow the reception of instructions from Earth? With this knowledge, the problem of backup receivers is completely solved. In this way, the engineers saved the mission (to ensure safety, in most of the subsequent flights of Voyager 2, before rendezvous, they always stored a scheduled collection of data on the computer on board, so that even if the spacecraft could not hear the request from their home again, it would not be in the way).
"Voyager 1" flying towards Saturn.
Another heartbreaking failure was that after the emergence of Voyager 2 from the back of Saturn in August 1981 (as it seems on Earth), the scanning platform was swaying like crazy—pointing everywhere for a very short time near Saturn, sometimes to the ring, sometimes to the moon or the planet itself. Suddenly, the platform got stuck. The scanning platform is a difficult situation that makes people crazy: you should know that spacecraft are flying over spectacular sights that we have never seen before. In the next few years or decades, we will never see them again, and the indifferent spacecraft is fixedly looking out into space without seeing anything.
scanning platform is driven by actuators with gear sets. So the jet propulsion laboratory engineers first used the same flight actuator in a simulation test, which failed after turning 348 times, while the actuator on the spacecraft failed after turning 352 times. The problem turned out to be caused by the lubrication failure. It is good to know this, but how to deal with it? It is clear that it is impossible to add a fuel refueler to the Voyager.
engineers consider whether their alternating heating and cooling can reactivate the failed actuator? Perhaps the resulting thermal stress causes the actuator's components to expand and contract at different rates and loosen it. They used special actuators to test this idea in the laboratory, and were excited to find that using this method they could restart the scanning platform in space. The designers also came up with ways to diagnose any other signs of actuator failure early, so there is enough time to work around the problem. Since then, the scanning platform of "Voyager 2" has been operating perfectly. Because of this work, all the pictures taken in the Uranus and Neptune system were found. The engineers won another victory.
Since Uranus and Neptune are both dark, the TV camera of "Voyager" has to be exposed for a long time. But the spacecraft is speeding, so the image becomes blurry.As compensation, the entire ship needs to rotate during exposure time to offset this movement. This matter is easy to say, but it is not. In the case of weightlessness, just the starting and stop of the tape recorder on the spacecraft will cause the spacecraft to gently shake and to the extent that the image is blurred. The solution to this problem is to issue instructions to the extremely sensitive small rocket engine (called thrusters) on the spacecraft. At the beginning and end of each data collection process, the thruster emits a little gas, causing the entire spacecraft to rotate slightly, thus compensating for the slight shaking of the tape recorder. To solve the problem that the radio signals received on the earth are too weak, engineers have designed a new and more effective way to record and transmit data, and connect various radio telescopes on the ground with electronic circuits, which can improve sensitivity. Overall, using many criteria to evaluate the operation of Uranus and Neptune is better than Saturn and even Jupiter.
"Voyager" is a wise existence - partly the artificial intelligence of automatic machinery, partly the wisdom of human beings. It extends human perception to distant astral bodies. For simple and short-term tasks, it relies on conscious wisdom; but for complex and long-term tasks, it requires the collective wisdom and experience of jet propulsion laboratory engineers. The two Voyager spacecraft reflect technology from the early 1970s. If spacecraft were designed for the same mission today, they would have adopted amazing progress in artificial intelligence , miniaturization, rapid data processing, self-diagnosis and remediation, and learning from experience, and they would be much cheaper.
The two "Voyager" spacecraft far exceeded the original design specifications and the best dreams of the developers. They represent the underlying elements of our nature, and want to travel freely in the solar system and farther space. The treasures discovered by this technology belong to people around the world and can be used by all mankind. Some people hate most of the United States' policies, and some agree with everything about it; but in recent decades, only a few of the United States' actions have been widely praised, and space exploration is one of them. "Voyager" costs less than a cent every year from launching to rendezvous with Neptune. I think the exploration of planets is one of the best things we do not only to the United States, but also to all mankind.
3 The final look back
spacecraft has been away from home, crossing the orbit of the outermost planet, and is flying away from the sun at a speed of 17 kilometers per second. But in early February 1990, it received an emergency order from the earth.
It turns the camera and points to the planet that is now far apart, turning its scanning target from one place in the sky to another. It took 60 photos and then sent the data back to Earth with radio waves. The spacecraft is 5.9 billion kilometers away from the earth, and it takes 5.5 hours to travel at the speed of light to receive it.
"Voyager 1" hangs high above the eclipse because it conducted a close-range probe of Saturn's giant moon Titan in 1981. Its sister spacecraft "Voyager 2" has different orbits and is in the ecliptic plane, so it can complete observations of Uranus and Neptune. The two Voyager aircraft inspected four planets and nearly 60 satellites, which were a victory for human engineering. When many other things in the contemporary era are forgotten, they will remain in history forever.
Two Voyager spacecraft are guaranteed to work until they meet with Saturn. I think it would be a good idea to give them a last glimpse of their homeland just after Saturn. I know that the Earth is too small from Saturn, so the Voyager cannot detect any details. Our Earth is just a spot of light, a lonely pixel, and it is difficult to distinguish from many other spots of light that Voyager can see (including nearby planets and distant stars). But it is precisely because this shows that our world is unobtrusive that such photos are worth taking.
Almost everyone has learned that the earth is a sphere, and we are all adsorbed by gravity. However, the real scenes of our world were not really seen clearly until "Apollo" took a famous photo full of frames on the entire earth. This photo was taken by astronauts from " Apollo 17 " during a recent flight to the moon by humans.
On December 7, 1972, astronauts of the American "Apollo 17" spacecraft took photos of the Earth from space on their way to the moon.
This photo can be said to have become a contemporary icon. This photo contains Antarctica. In addition, the whole of Africa is shown in the photos: you can see the earliest humans inhabited Ethiopian , Tanzanian and Kenya . On the top right is Saudi Arabian , and on the top is Mediterranean , a large part of the civilization of the entire world appears around it. You can recognize the blue of the ocean, the yellow and red of the Sahara and the brown and green of the Arabian desert , and the brown and green of the forests and grasslands.
However, there is no sign of humanity in this photo, and we cannot see the transformation of the earth's surface. We are too tiny to see on the spacecraft located between the Earth and the Moon. The Earth photo of "Apollo" tells the masses something familiar to astronomers: on the scale of planets (not to mention stars and galaxies), human beings are insignificant, it is nothing more than a thin layer of life on a mixed rock and metallic body of remote and lonely rock.
I think it would be helpful to take another photo of the earth from a distance of tens of millions of times more to understand our true environment and situation. Ancient scientists and philosophers have already known that the earth is just a small one in the vast and all-encompassing universe, but no one has seen an earth like this. Here is our first (and perhaps the last) chance in the next few decades.
Many people at NASA who work on the "Voyager" program support me. However, from the perspective of the outer part of the solar system, the earth is very close to the sun. Are we willing to risk the video tubes on the spacecraft being burned and put the camera tightly towards the sun? Should I wait until all the scientific photos taken from Uranus and Neptune are taken before taking this photo? Is this better?
So we waited, from the detection of Saturn in 1981, to the detection of Uranus in 1986, and to the orbits of Neptune and , Pluto in 1989, the time finally came. , but several designers still objected. They say it's not science. We then discovered that technicians employed by the National Space Administration who designed and sent radio instructions to "travelers" were about to be fired or transferred to other jobs due to the tightening of the agency's funding. If you want to take a picture, you must do it immediately. At the last minute—actually when Voyager 2 met Neptune—the then Chief Executive of the National Space Administration and Rear Admiral Richard Truly intervened and decided to take the photos. Candy Hansen, a space scientist at the Jet Propulsion Laboratory under the National Space Administration, and Carolyn Porco from the University of Arizona , designed the instruction program and calculated the exposure time of the camera.
So they are here - is around the planet and on a set of square frame mosaics scattered on the background of distant stars. We photographed not only the Earth, but also five of the other nine known planets of the Sun. The innermost Mercury is submerged in the sun's light, Mars and Pluto are too small, too dark, and the latter is too far away. Uranus and Neptune are very dark, and it takes a long exposure time to photograph them; therefore their images are blurred due to the movement of the spacecraft. This is the image of the planet it sees when it approaches the solar system after a long interstellar voyage.
[Note: On August 24, 2006, after voting by the International Astronomical Federation Conference, Pluto was excluded from the ranks of planets.】
even uses a high-resolution telescope loaded by the Voyager. From such a distance, the planets are just some blurry or non-blurred spots of light. They are like planets seen with the naked eye on the surface of the Earth, i.e. some light spots that are brighter than most stars. By simply watching one of these spots of light, you can't tell what it is, what it is on it, how it was in the past, and whether there are currently people living there.
Because the sunlight reflects on the spacecraft, the earth seems to be in a beam of light, which seems to have some special meaning for this small world. But this is only an accident caused by geometry and optical causes. The sun emits radiation evenly in all directions. If the photo was taken a little earlier or a little later, there would be no strong sunlight on the earth.
Look at that light spot again, it is here. This is home, this is us. Everyone you love, everyone you know, everyone you have heard of, everyone you have ever had, have spent their lives on it. Our joy and pain are gathered together, thousands of self-righteous religions, ideology, and economics, every hunter and fodder collector, every hero and coward, every civilization creator and destroyer, every king and farmer, every young couple, every mother and father, hopeful children, inventor and explorer, every respected teacher, every corrupt politician, every "superstar", every "super leader", every saint and criminal in human history, are here - a small dot of dust suspended in the sun.
In the vast cosmic theater, the earth is just a very small stage. Think about all the emperors and generals who killed each other and slaughtered blood, their glory and victory made them the fleeting masters of a part of the light spot; think about the endless cruel crimes committed by the residents of one corner of this pixel to the residents who had almost no difference in some corner, how many misunderstandings they had, how eager they were to kill each other, how strong their hatred was.
Our mood, our fictional arrogance, our illusion of having a certain privileged position in the universe, are all challenged by this pale light spot. In the vast dark universe that embraces everything, our planet is a lonely spot. Due to our low status and vast space, there is no hint that there will be a savior from somewhere else to save us from our situation.
Earth is currently the only world where life is known to exist. At least in the near future, human beings will not be able to move to other places. Visits are possible, but settlement is impossible. Whether you like it or not, for now, the earth is also where we live.
Someone said that astronomy makes people feel inferior and can cultivate personality. Apart from this distant image of our little world, there is probably no better way to reveal how stupid it is to be human arrogance. It is our duty to interact more friendly with each other and to protect and cherish this pale blue spot of light – the only home we know so far.
4 Flying at the edge of the solar system
"Voyager" spacecraft is flying to the stars. The gravitational field of Jupiter, Saturn, Uranus and Neptune all ejected them at a very high speed, allowing them to finally get rid of the constraints of the sun's gravity on them.
Voyager 2 shot a corner of Jupiter's moon Europa.
Have they left the solar system? The answer is closely related to how you define the boundaries of the "Sun Kingdom". If the boundary was the orbit of a considerable outermost planet, then the Voyager spacecraft had already run out, because there were probably no planets of similar size to Neptune that had not been discovered. If you are referring to the outermost planet, then far away from Neptune and Pluto, there may be other planets similar to Triton . If so, then Voyager 1 and Voyager 2 are still within the solar system.If you set the outer edge of the solar system as the top of the solar wind layer—where interplanetary particles and magnetic fields are replaced by interstellar particles and magnetic fields—then neither Voyager spacecraft have left the solar system, and in a few decades, they may fly out. However, if you define the edge of the solar system as the distance the sun can no longer control the stars orbit it in orbit, then Voyager will not leave the solar system for hundreds of centuries.
[Note: In September 2013, NASA announced that it had confirmed that "Voyager 1" had left the top of the solar strata. 】
There are trillions or more comets gently caught by the sun's gravity in any direction in the sky. They accumulate into a huge group, which is Ort Cloud . It will take about 20,000 years for the two spacecraft to pass through the Olt Cloud. After that, the two "Voyagers" will sail towards the vast ocean of interstellar space. Only then will their second phase detection begin. By then their radio transmitters had long failed, and the two spacecraft would roam in quiet, cold and dark interstellar space for a long time, with almost nothing eroding them. Once out of the solar system, they will remain intact for a billion years or more, and they will orbit the center of the Milky Way .
We don’t know if there are other intelligent creatures in the Milky Way engaged in space exploration. If they do exist, we don’t know how many they have, let alone where they are. But there is at least one chance that at some point in the distant future, a Voyager will be intercepted by an alien spacecraft and conducted an investigation.
Because of this, when each Voyager leaves the earth, it carries a gilded record.
is particularly worth mentioning that the record records contain the following information: greetings from 59 human languages and a whale's voice; a 12-minute sound integration, including kissing, baby crying, and brain waves images of a young woman in love meditation; 116 coded pictures, including human science, civilization and ourselves; and 90 minutes of the most popular music on the earth — Eastern and Western, classical and folk, including the Navajo night hymns, Japanese dramas, pygmy girls’ coming-of-age songs, Peruvian wedding songs, a Chinese guqin song "Flowing Water" composed 3,000 years ago; there are also Bach, Beethoven, Mozart, Stravinsky, Louis Armstrong Works by musicians such as Armstrong, Blind Willie Johnson and Chuck Berry.
space is almost empty, so no Voyager spacecraft actually has a chance to enter another solar system—even if every star in the universe is accompanied by planets. Only in the distant future, when aliens in some place discover the "Voyager" deep in interstellar space, can we think that the instructions written on the record cover with easy-to-understand scientific symbols will be read and the content of the record will be understood. Because the two "Voyagers" will always orbit the center of the galaxy, the record will take long enough to make people discover it - if there are aliens to discover it.
We don’t know how much they will know about the content of the record. It is certain that they don’t understand the greetings, but the intention of the greetings may be heard. Our imaginary aliens must be different from us, because they evolved independently from another world. Do we really believe they can understand all the information we send? Every time I hear these things that people care about, I feel uneasy. However, I still comfort myself: no matter how much the Voyager record is, any alien spacecraft that discovered it will evaluate us with another standard. Each "Voyager" is itself a message, their spirit of adventure, their lofty pursuit of their own goals, their total unintentional harm to others, and their outstanding design and performance, these two robots eloquently tell us all.
But those aliens must be scientists and engineers who are much more wise than us—or they would never be able to find and recycle this small, silent spacecraft in interstellar space—maybe they will understand the message conveyed by the gilded record without any difficulty. Perhaps they will recognize the instability of our society and how disproportionate our technology is to our wisdom. They might wonder whether we have destroyed ourselves after launching the Voyager or continue to pursue a greater cause?
Maybe these records will never be intercepted. Maybe no one will encounter them within 5 billion years. 5 billion years are long years. In 5 billion years, all human beings must have become extinct or evolved into other creatures. No artificial things will remain on the earth. The continent must have completely changed or destroyed. The evolution of the sun must have burned the earth into scorched earth or converted it into a large pile of disordered atoms.
By that time, the two Voyager spacecraft would not be affected by these distant events. They would continue to fly with memories of this no longer existential planet.
Carl Sagan (November 9, 1934 - December 20, 1996), an American astronomer, astrophysicist, and cosmologist.
"Dark Blue Dot"
People's Posts and Telecommunications Press
This book is the 80th anniversary of the birth of Sagan's classic work.
represents one of the top 100 books in the 20th century.
is a grand masterpiece that depicts the coordinates and status of human beings in the universe.
The sister chapter of the best-selling book of the same name in the classic documentary "The Universe",
Open this book,
You have a brand new world in your hands.
