The world's top cosmic photography works

In 1980s, Carl Sagan, a famous astronomer, traveled all over the National Aeronautics and Space Administration (NASA) and visited officials and technicians of NASA, hoping to persuade them to turn the voyager 1, which is billions of kilometers away, to 180 degrees.

Frankly speaking, Sagan's request is very strange, because everyone knows that Voyager 1 can't take a clear picture of the earth billions of kilometers away, so although Voyager 1 had detected Jupiter and Saturn and their moons at that time, and its primary task had been completed, NASA was still unwilling to spend precious fuel to make Voyager 1 turn around and take a picture of the earth that was doomed to be unclear.

Seeing that NASA insisted on not letting Voyager 1 go back to shoot, carl sagan began to use his influence to directly negotiate with NASA's superior unit, the Washington General Administration, hoping to give orders to NASA by persuading them to control Voyager 1.

Facts have proved that carl sagan's action was very effective, because he was the best popular science writer and popular science documentary host on the earth at that time. As early as 1980, he became famous all over the world with 13 astronomical documentary "Carl Sagan's Universe". This documentary has been watched more than 600 million times in more than 60 countries, and he was quickly persuaded with a celebrity aura.

At carl sagan's request, NASA issued an order to Voyager 1, which is 6.4 billion kilometers away: look back and look back at the planets it detected, and photograph these planets, and synthesized a family portrait of planets of the solar system consisting of 60 photos, including 6 planets in the solar system.

In this noisy photo, there is a slightly white point at the end of a beam of light. It's the earth, taken from 6.4 billion kilometers away. But it is different from the familiar blue marbles. In the long distance of 6.4 billion kilometers, the earth is only 0. 12 pixels, just a bright spot, like a hurricane lamp that will go out at any time in the universe, like a dust suspended in the sun.

But in this dust, everyone you love, everyone you know, everyone you have heard of, all saints and sinners throughout the ages, every founder or destroyer of civilization, and every great parent or child with the purest eyes exist in this dust.

After this photo was sent back to Earth, carl sagan explained the story of this photo and the meaning behind it on live TV. Because the earth emits dim blue light in the sun's light path refracted by the detector, this photo was finally named "Dim Blue Dot", which became a celestial photography with the same name as "Blue Marbles" and "Moon" because they both expressed the smallness of the earth and human beings.

At the end of the live TV broadcast, carl sagan expressed the hope that through his own efforts, more people would think about the fate of mankind and the earth and make clear our position in the universe. At the same time, he hopes that when we see the tiny earth, we can treat everyone around us more kindly and sympathetically, and cherish and protect this dim blue spot more, because it is the only home known to mankind at present.

Because today, 25 years after carl sagan's death, more than 4,000 exoplanets have been discovered in astronomy, and the number is still increasing at the rate of one per day. Among the more than 4,000 exoplanets, some have been proved to be similar to the Earth, namely the so-called super Earth and the second Earth.

Although these potential livable planets are dozens or hundreds of light years away, their existence at least proves that the earth is not special in the universe, and human civilization does not need to worry about having no place to live after leaving the earth. At the same time, life and even civilization may be born on these planets, because their conditions are similar to those of the earth. The evolution of life that occurred in the depths of the earth's oceans 3.8 billion years ago may also be repeated on these planets.

After all, the solar system where the earth is located is just one of the hundreds of millions of star systems in the Milky Way. Located in the desolate corner of Orion's spiral arm in the Milky Way, the solar system needs 220 million years to make a public turn around the center of the Milky Way, and the red Supergiant star Shield UY, which is 9,500 light years away, can accommodate 5 billion suns.

These data far beyond human cognition remind us all the time that in the Hubble volume with a diameter of 93 billion light years, human status is not worth mentioning, just a group of bacteria crowded on a cloud of dust.

Carl Sagan insisted that Voyager 1 return to shoot the earth, probably to make most people realize their smallness in the universe and the instability of the earth in the universe.