The process of spatial migration

Go to the moon first-this is a transit station, followed by Mars, which is more likely to be inhabited. As for Venus, because there are no conditions suitable for human habitation, it is not suitable for living.

Venus is similar to the earth in terms of size and mass. The diameter of Venus is only 653km smaller than that of the Earth, that is,12103km. The mass of Venus is about 8 1% of the mass of the earth. However, in other respects, Venus has little in common with the Earth. Venus is completely surrounded by thick clouds, which mainly contain droplets of concentrated sulfuric acid. The main cloud layer extends from about 45 kilometers above the surface to about 70 kilometers. The mist extends thousands of meters from the lowest layer of thick clouds and about 20 kilometers upward from the highest layer. Observed by ultraviolet light, some cloud top areas appear dark, which may be due to the presence of sulfur dioxide, sulfur chloride, chlorine gas or solid sulfur.

Venus has a relatively flat surface, because it is protected by dense atmosphere, unlike the Moon, Mercury and Mars, which have many craters. There are also some mountains or mountains on Venus, some of which can reach hundreds of kilometers in diameter, but they are generally not too high. Its equatorial region has some large and shallow circular circles like craters, and there is a great rift valley running through the equator 1200 km from south to north. Most of the surface of Venus is covered, and the thickness is generally less than one meter. Below this caprock are basalt, igneous rock and other rocks. Venus has a high surface temperature and no liquid water. Coupled with harsh natural conditions such as extremely high atmospheric pressure and severe hypoxia, it is of course impossible for any animals and plants like the earth to exist.

There is no direct data about the internal structure of Venus. Theoretically, it is concluded that the internal structure of Venus is similar to that of the Earth, with an iron-nickel core with a radius of about 3 100 km, the middle layer is a "mantle" mainly composed of silicon, oxygen, iron, magnesium and other compounds, and the outer layer is a very thin "shell" mainly composed of silicon compounds.

The composition of Venus' atmosphere is completely different from that of the earth's atmosphere. Measurements by space probes show that carbon dioxide accounts for more than 96% of the constituent substances, which makes Venus's atmosphere have a great density. Nitrogen accounts for 3.5%; There are also traces of argon, water vapor, carbon monoxide, helium and sulfur monoxide. The dense atmosphere and thick clouds effectively capture the incoming solar energy, making the surface temperature of Venus as high as 460 degrees Celsius, the highest among all planets in the solar system. 30 ~ 40 kilometers away from the surface of Venus, there are dense clouds with a thickness of 25 kilometers, which can reflect about 75% of the incident sunlight. The thick clouds are composed of micron-sized concentrated sulfuric acid fog, and the outside of the clouds is basically atomic oxygen. The carbon dioxide in Venus' atmosphere has a very strong greenhouse effect, which makes the surface temperature of Venus as high as 465 ~ 485℃, basically regardless of region, season and day and night. According to the Venus probe, the temperature in the Arctic is about 10℃ higher than that in the equatorial region where the sun shines. With the increase of altitude, the temperature in the atmosphere drops, and the temperature at the top of the atmosphere is -55℃. The lower atmosphere near the surface of Venus is generally quiet, and the wind speed is only about 2 meters per second. But there is a large circulation at the top of the atmosphere, which rotates in the same direction and the speed can reach 320 kilometers per hour.

Venus, unlike other big planets, rotates reversely from east to west and slowly rotates once every 243 days. Venus' axis of rotation has an inclination of only 3 degrees with respect to its orbital plane around the sun. These facts show that its seasonal changes are inevitably not obvious. The heating of the sun and the slow rotation of Venus lead to an atmospheric circulation. The air rises in the equatorial belt due to heating, slowly moves to high latitudes, and then reaches the polar regions. Then, the air cools and sinks, and then returns to the equatorial belt along the surface. Such a simple model, if placed on the rapidly rotating earth, will be completely unstable. There is also obvious instability on Venus, which shows a strong wave pattern, changing the above simple situation. The rotation speed of the atmosphere also increases with the height from the surface to the upper atmosphere. In this way, the observed cloud area revolves around the equator of Venus every four Earth days.

The atmospheric pressure on the surface of Venus is about 90 times that of the earth, and the discharge is very frequent. Venus probe once recorded a big lightning that lasted 15 minutes. The dense Venus atmosphere also caused a peculiar optical phenomenon, that is, atmospheric refraction can bend sunlight to the direction close to the horizon 180. So on Venus, even with your back to the sun, you can enjoy the wonders of "Sunset East Mountain".

Venus basically has no magnetic field (the intensity is less than one tenth of the geomagnetic field), and no radiation belt has been found. Solar wind, ultraviolet rays and X-rays can penetrate deep into the atmosphere, ionize part of the atmosphere, and produce a very thin Venus ionosphere, which is very close to the surface of Venus. The electron density in the ionosphere is very low at night.