More than 30 years ago, on February 14, 1990, NASA's Voyager 1 probe, which was flying beyond the solar system, turned the lens to take pictures of the sun and the eight planets, forming a family portrait of the solar system.
Among them, a photo taken of the earth called "dim blue dot" is the most classic. In this photo, the earth is just a bright spot, the size of the earth is only 0.12 pixels of the entire photo, it is suspended in the dark background, it looks very small, very inconspicuous, like a grain of dust in the universe. The photo uses a narrow-angled camera on the Voyager 1 probe and uses blue, green and purple filters.
The Voyager 1 probe was launched on September 5, 1977, and by the time this image was taken, Voyager 1 had already visited Jupiter and Saturn, completing its important mission at the beginning of its launch. At that time, it was about 6.4 billion kilometers from Earth, had been flying in the solar system for 13 years, and had already leapt into the orbit of Neptune, the outermost of the eight planets in the solar system.
Since Voyager 1 was already far from Earth when it took this photo, it was teleported back to Earth, and people on the ground didn't receive it until about 6 hours later.
The "dim blue dot" should be one of the most classic photographs of the earth in human history. It is said that the famous American science fiction writer and astronomer Carl Sagan also got inspiration for this photo and wrote the book "PaleBlueDot".
The reason why such a small photo is so classic is because this photo is a very vivid reminder of human beings, making people think deeply, the universe is really too big, and human beings are really small in the universe. If the earth is a grain of sand in the universe, then humans are the bacteria that live on this humble grain of sand. But it was such a small grain of sand that gave birth to such an intelligent life as human beings.
For a long time when Copernicus proposed the heliocentric theory, most people thought that the earth was the center of the universe. At the beginning of the last century, human beings discovered extragalactic galaxies, and it turned out that not only was the earth not the center of the universe, but the sun and even the Milky Way were not the center of the universe. These new cognitions have brought a huge psychological gap to people.
For a long time, humans have been exploring the secrets of the night sky, especially the emergence of telescopes centuries ago, which greatly improved human understanding of the universe. But until the advent of satellites in the 1960s, humans never saw a complete image of the Earth.
Ever since humans have been able to go into space, both probes and astronauts have always liked to admire the Earth from distant places and take photos of it.
In 1968, the Apollo 8 spacecraft, in orbit around the moon, took a meaningful "ground-out" photo of the Earth. In the photo, the Earth and the Moon swap roles, and the Earth is like a bright moon slowly rising from the moon's horizon.
On December 7, 1972, American astronauts took a picture of a blue marble 45,000 kilometers from Earth while on the last lunar mission aboard the Apollo 17 spacecraft. Among the many photographs that encompass the entire Earth, this one is one of the most perfect passport photographs of the Earth taken in that era, so it is widely circulated.
Before the "Dim Blue Dot" photo came out in 1990, humans had never looked at the Earth from such a long distance and taken pictures of the Earth. Before that, most people saw the earth as beautiful, majestic, and spectacular, never so small, as small as a grain of sand.
In fact, even if we don't have such a long distance, we can feel the smallness of the earth. Just as humans look at Mars and Jupiter from Earth, they are just a small star in the night sky of The Earth, and if we look at the Earth from the orbit of Jupiter, it is only a star. If we look at the Sun from the orbit of Pluto, the Sun is just a star.
More than 30 years later, the Voyager 1 probe has not yet flown out of the solar system, but has entered interstellar space. As one of the five farthest probes launched by humans, the image taken by Voyager 1 at a distance of 6.4 billion kilometers is also the best record of a small step in the process of human exploration of the universe.
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