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Are there other lives in the universe? Alien?

   Except for the earth, other planets in the solar system are not suitable for human survival. We humans are unique in the solar system. Outside the solar system, are there any intelligent creatures similar to humans?

   There are more than 100 billion stars in the Milky Way, and some scientists have estimated that there are about 1 million stars like the sun suitable for biological evolution. In addition to the Milky Way, there are thousands of galaxies similar to the Milky Way, and there should also be numerous planets and star systems. Do intelligent creatures exist in all planets and star systems? The proliferation and survival of intelligent creatures must meet certain conditions. First of all, life can only survive on non-luminous planets with solid surfaces. Moreover, the mass and size of this planet must be moderate, and its gravity must be able to confine a large amount of gas to form an atmosphere. It must be contained in the atmosphere

  Enough oxygen, and enough moisture on the surface, these are all

   The necessary conditions for life to survive. Secondly, the central star surrounded by this planet must be a stable star. If it is a variable star that is sometimes quiet and sometimes erupts, it will not work. once it loses its temper, not only the people on the planet will not be able to stand it, but the planet itself will also be burned.

   Many conditions are needed to sustain life on planets, but scientists still believe that there are many planets suitable for life in the universe. According to calculations by astronomers, there are more than 100 billion stars in the Milky Way, and around them there are about 15 million planets that are similar to the Earth's environment. But these planets are too far away from the earth, we can't know everything there.

   Recently, astronomers discovered a planet outside the solar system that is similar to the Earth in all aspects.

This has to make people think about whether there is anything close to life on the earth? But this planet is 56 light-years away from the earth. How far is this distance? Let’s take the nearest star "South Gate 2 Half Sagittarius Alpha" as an example. It is 4.2 light-years away from the earth. If you take an airplane at a speed of 1,000 kilometers per hour, it will take 4.6 million years to fly. Arrival. If you take a spaceship of 1,000 kilometers per second, it will take 12,800 years to reach it.

And the distance of this planet from the earth is 13 times that of "South Gate 2 Half Sagittarius-Alpha". Obviously, it is impossible to get there. Because at present, no life entity on the earth can complete such a long distance. Travel.

Scientists believe that "Aliens' may exist. In order to explore the traces of aliens, scientists have made a lot of efforts. Presenting aliens with "Earth Business Cards" is one of them. One of the means. In March 1972 and April 1973, the United States successfully launched the Pioneer 10 and Pioneer 11 probes.

They carry two identical "Earth Business Cards" and fly away from the solar system, looking for "aliens..." in the vast universe. This "business card. It is a gold-plated aluminum plate." The right half of the business card is mainly a portrait of a man and a woman, representing human beings on the earth. Although the form of "alien" may be very different from ours, scientists still believe that the image of humans is unlikely to be misunderstood.