This photo taken 6.4 billion kilometers away has refreshed people's understanding of the earth.

So far, mankind's space journey has brought back countless images, one of which is particularly special. It has no high-definition picture and bright light, but it has refreshed human cognition of the earth.

This photo, the "dim blue dot" taken by navigator 1 at a distance of 6.4 billion kilometers from the earth, is one of the most famous photos in astronomy.

What's on the detector?

Are there aliens in the universe? If we were to be introduced to them, what would this "self-introduction" look like?

1 September 5, 977, the traveler1set out in Florida, USA, carrying the "self-introduction" of human beings.

It contains a gold-plated record made of copper, on which the greetings of "Children on Earth (Say Hello)" are said in 55 languages (including English, four China languages (Mandarin, Minnan, Cantonese and Wu). Even after 1 billion years, the quality of these sounds will not change.

In addition to greetings, there are 27 classical music of different cultures in the record; And 1 15 video materials, including photos of major planets in the solar system, pictures and descriptions of human reproductive organs, etc.

At the same time, then US President Carter also left his greetings:

This record can be regarded as a greeting to possible alien life, and also a record and proof of the existence of human civilization.

Voyager 1 space travel

Although Voyager 1 is loaded with information and greetings from human civilization, its main purpose is not to find extraterrestrial life, but to explore Jupiter and Saturn.

The expedition plan originated from a discovery. In the late 1970s, scientists observed the once-in-a-lifetime planetary geometric arrangement of 176: Jupiter, Saturn, Uranus and Neptune would all run to the ideal place for boosting and form a queue.

If detection is carried out at this time, humans can only visit once; If we miss this opportunity, the next opportunity will wait until the 22 nd century.

In order to start this exploration, the United States mobilized tens of thousands of scientists and engineers to send Voyager 1 and Voyager 2 into space from August 20th to September 5th, 1977.

As the first "big brother", Voyager 1 explored Jupiter's satellite, ring, magnetic field and radiation environment for the first time and took 33,000 clear photos.

For example, this photo captures the beautiful "Great Red Spot" above Jupiter, which is Jupiter's atmosphere.

Before that, people saw few photos of Jupiter, and they were all blurred.

1980, Voyager 1 passed Saturn and still sent back tens of thousands of high-definition photos. For example, in the photo below, we can clearly see the beautiful rings of Saturn.

Later, Brother Voyager 1 left the ecliptic plane and handed over the task of exploring Uranus and Neptune to Brother Voyager 2. The former moved on, 1990, about 4 billion kilometers away from the earth, heading for the edge of the solar system.

At a distance of 6.4 billion kilometers from the earth, the traveler 1 who completed the exploration mission turned off some equipment to save energy. Before turning off the camera, NASA turned it around and took the last photo of the space trip.

It took several hours to send this photo back to earth, and the traveler 1 continued to move to the edge of the solar system, farther and farther.

This is a photograph of the solar system. This photo is dark, and many planets are not as big as 1 pixel, but this photo is of great significance.

If you enlarge the photo, you can find the earth where we live. In this 640,000-pixel photo, the earth is just a dim dot with 0. 12 pixels.

This photo is called "dim blue dot", and the blue planet we live on is as small as a dust in the vast solar system. This is also a comparison of the solar system. There is a wider universe outside the solar system, where there are other galaxies.

The third season of National Treasure shows the universe in the "Golden Pearl Celestial Sphere". As it flies farther and farther, the earth gradually changes from a huge blue planet to a small light spot and finally disappears.

If we fly outward from the earth, then the diameter of our flying out of the earth is 1.33 million kilometers; Then we can see the whole solar system, including the sun, 8 planets, 205 satellites and 500,000 asteroids.

Continue to fly outward, we see the Milky Way, and the solar system is just on a relatively small spiral arm of the Milky Way; Outside the Milky Way, it is an extragalactic galaxy. ...

Compared with the universe, we live on the earth so small. Whether you are a lover, a friend or someone you have never heard of, you live in this little dust.

But we are so small, but we often claim to be the masters of the earth, controlling the environment and creatures. ...

The reason why "dim blue dot" touches everyone is not because it is beautiful, but because it refreshes human's understanding of the earth: human beings and even the earth are just a drop in the ocean for the universe, and we are so small in the vast universe.

At this moment, our feelings, our arrogance and our illusion of our privileged position in the universe are all so insignificant in front of the "dim blue dot".

This tiny "light spot" makes us even more humble, and also makes us think deeply about our situation and our responsibility to all mankind.

————————————