What do people want to get rid of when they want to leave the solar system?

Ever since human beings entered the space age in 1950s, it has been the dream of countless people to fly out of the solar system and roam the Xinghai. In the vast and magnificent universe, although the solar system is as small as dust, it is not as simple as imagined to leave this "cradle" of human civilization.

Scientists' definition of the boundary of the solar system is still controversial. One theory holds that the solar wind has the greatest influence and the heliosphere is the final boundary of the solar system. Its radius is about 120 astronomical unit (1AU, that is,1500,000 km). Breaking through this "barrier" means getting rid of the solar magnetic field and entering interstellar space.

How big is the heliosphere? Because the solar activity takes 22 years as a cycle, the size of the heliosphere will change accordingly. In addition, as the sun moves in the Milky Way, the heliosphere will shrink in the direction of the sun and extend in the opposite direction. If the particle density around the deep space probe suddenly drops, scientists can judge that it is no longer blown by the solar wind and has stood on the "threshold" of the solar system.

So far, there are two probes that humans have officially entered interstellar space, namely Voyager 1 and Voyager 2, which were launched in 1977, and the distances from the Earth are 21700 million kilometers and1800 million kilometers respectively. Two other probes launched before-1pioneer in 972 and1pioneer in 97311-are also pushing towards the edge of the solar system.

According to a set of data released by NASA on 20 17, Pioneer 10 has flown to the place where it is away from the Earth 1 18.824AU, far exceeding other detectors except Voyager 1. However, because it's heading in the opposite direction to the direction in which the sun moves around the center of the Milky Way, the heliosphere here is 220AU thick.

Pioneer 1 1 Like the traveler's brother, it is in the same direction as the revolution of the sun. As of 20 17, it has been 97.6AU away from the earth, and will enter interstellar space in 2027 according to the calculation of flying 2.3AU a year.

Later, the New Horizon probe was launched at a faster speed, and it could sail 3. 1AU every year. It is expected to leave the embrace of the sun in 2043.

Of course, if the Oort cloud from the sun 1000 to 100000 au is regarded as the real boundary of the solar system, then the farthest traveler 1 will completely cross it after 56000 years!

In any case, these human "messengers" will eventually leave the solar system and wander in the boundless universe. Some people may worry that the information they carry about the coordinates of the earth will be discovered by alien civilizations, thus endangering the survival of mankind, but in fact this kind of worry is completely unnecessary-the emptiness of the universe far exceeds our imagination, and the chances of human detectors encountering other celestial bodies are extremely small. On the other hand, since the beginning of the last century, the radio signals sent by human civilization have been spreading to the universe, reaching as far as 1 19 light years, and the "Arecibo information" for the cluster M 13 also covers 45 light years. If there are advanced intelligent creatures in this range, maybe they already know the whereabouts of human civilization.