Venus, Jupiter and Saturn, which is more suitable for human habitation?

Overview of Venus Some people say that Venus is the twin sister of the earth. Indeed, from the structural point of view, Venus and the Earth have many similarities. Venus has a radius of about 6,073 kilometers, only 300 kilometers smaller than radius of the earth, its volume is 0.88 times that of the Earth, and its mass is 4/5 of that of the Earth. The average density is slightly less than that of the earth. But the environment between them is very different: the surface temperature of Venus is very high and there is no liquid water. Coupled with cruel natural conditions such as extremely high atmospheric pressure and severe hypoxia, Venus cannot have any life. So Venus and the Earth are just sisters.

Venus's rotation is very special. Its rotation direction is opposite to that of other planets, from west to east. Therefore, on Venus, the sun rises in the west and sets in the east. It takes 243 days to rotate once, but the day and night on Venus are particularly long, which is equivalent to 1 17 days on Earth. This means that Venus only has two days in a year, and only two days can be seen in a year. Venus's orbit around the sun is an ellipse that is very close to a perfect circle. Its revolution speed is about 35 kilometers per second, and period of revolution's is about 224.70 days. Venus's orbit is very close to a perfect circle and coincides with the ecliptic plane. Its period of revolution is about 224.7 days, but its rotation period is 243 days. That is to say, Venus's "one day" is longer than its "one year". Venus is the only big planet in the solar system that rotates in the opposite direction. Besides, like Mercury, it is the only two planets in the solar system without natural satellites. The day and night of Venus is 243 days, and that of period of revolution is 225 days. Venus' slow rotation is retrograde, that is, it rotates from east to west, not from west to east like most planets (Pluto and Uranus are also retrograde, and Uranus' axis of rotation is tilted 97.86 degrees, almost perpendicular to the orbital plane). This phenomenon may have been caused by the collision of Venus with other asteroids a long time ago, but it has not been proved yet. In addition to this unusual retrograde, Venus is a little unusual. Venus' rotation period and orbit are synchronized, so that when the two planets are closest, Venus always faces the earth with the same face (once every 5.00438+0 Venus days). This may be the result of tidal locking's action-when the two planets are close enough, tidal force will affect the rotation of Venus. Of course, it may just be a coincidence.

Main parameter

Period of revolution: 224.70438+0 days.

Average orbital speed: 35.03 km/s.

Track eccentricity: 0.007

Track inclination: 3.4 degrees

Equatorial diameter: 12,103.6km.

Mass (Earth mass = 1): 0.8 150.

Density: 5.24 g/cm3

Rotation period: 243.0 1 day.

Number of satellites: 0

Radius of revolution:108,208,930 km (0.72 astronomical unit)

The surface area is 460 million square kilometers.

Surface gravity 8.78m/s2

Autobiography time -243.02 days

Escape velocity10.4km/s

The lowest average surface temperature is the highest.

737K 750K 773K

topography

There are two main continental highlands on the great plains on the surface of Venus. The highland in the north is called Ishtadi, where there is the Maxwell Mountains with the highest Venus (about two kilometers higher than the Himalayas). It was named after james clerk maxwell. The Maxwell Mountains surround the Laxmi Plateau. Istar is about the size of Australia. There is a larger land of Aphrodite in the southern hemisphere, the area of which is equivalent to that of South America. There are many vast lowlands between these highlands, including the lowlands in Taranta Plain, the lowlands in Genneville Plain and the lowlands in lavinia Plain. Except Maxwell Mountains, all Venus landforms are named after real or mythical women. Because Venus' thick atmosphere slows down the speed of meteors and other celestial bodies before reaching the surface of Venus, the crater on Venus is no more than 3.2 kilometers.

About 90% of the surface of Venus is formed by basalt lava solidified not long ago, but there are also a few craters. This shows that Venus is currently undergoing surface reconstruction. Venus may be similar to the earth inside: the core with a radius of about 3000 kilometers and the mantle composed of lava make up most of Venus. The latest data from Magellan shows that the crust of Venus is thicker and stronger than previously thought. It can be inferred that Venus has no movable plate structure like the Earth, but there are a lot of regular volcanic eruptions on its surface. The oldest feature on Venus is only 800 million years old, and most areas are quite young (but it is also hundreds of millions of years old). Recent discoveries show that Venus' volcanoes are still active in isolated geological hotspots.

Compared with other planets in the solar system, the magnetic field of Venus itself is very weak. This may be because Venus does not rotate fast enough, and the liquid iron in its core is weak because of cutting the magnetic induction line. In this way, the solar wind can hit the upper atmosphere of Venus without any buffer. At the earliest time, people thought that Venus and the water on the earth were equal in quantity. However, the attack of the solar wind has decomposed the water vapor in the upper atmosphere of Venus into hydrogen and oxygen. Hydrogen atoms escape into space because of their low mass. The proportion of deuterium (an isotope of hydrogen, heavier and slower to escape) on Venus seems to support this theory. And oxygen combines with substances in the earth's crust, so there is no oxygen in the atmosphere. The surface of Venus is very dry, so the rocks on Venus are harder than those on the earth, thus forming steeper mountains, cliffs and other landforms.

In addition, according to the detection of the detector, it is found that the magma of Venus contains water.

Venus may have a lot of water like the earth, but it was evaporated and dissipated, so it is very dry now. If the earth were closer to the sun, it would have the same luck. We will know why the basic conditions are so similar but there are so different phenomena.

Most of the surface of Venus consists of slightly undulating plains, and there are also several broad depressions. There are also two big highlands, the plateau, surrounded by the highest mountains on Venus.

There are no small craters on Venus, and it seems that asteroids were not burned out when they entered the dense atmosphere of Venus. The craters on Venus are all in strings, which seems to be because large asteroids usually split in the atmosphere before reaching the surface of Venus.

The oldest region on Venus seems to have been formed 800 million years ago. At that time, a wide range of mountain fires scrubbed the early surface, including several large craters formed in the early history of Venus.

Venus has no magnetic field, which may be caused by the slow rotation speed.

Venus has a relatively young surface, which was formed about 3 million to 5 million years ago. The terrain of Venus is relatively flat. Venus is 70% flat, 20% low, 10% highland. The highest peak 10590 m is higher than Mount Everest. A grand canyon 1200 kilometers long, which runs through the equator from south to north, is the largest canyon among the nine planets.

There are no small craters on Venus. Due to the dense atmosphere on the surface of Venus, minior was burned when it entered the atmosphere of Venus. Craters on Venus are usually clustered, probably because larger asteroids disintegrated in the atmosphere before reaching the surface of Venus.

Volcanoes and Volcanic Activities Venus has many surfaces. At least 85% of Venus is covered by volcanic rocks. In addition to hundreds of large volcanoes, there are more than 100000 small volcanoes scattered on the surface of Venus. The lava flow from the volcano has produced long ditches, with a range of hundreds of kilometers and the longest exceeding 7000 kilometers.

Volcanic distribution on Venus

Venus is densely covered with volcanoes, which is the planet with the largest number of volcanoes in the solar system. Venus and the earth have a lot in common. They are similar in size and volume, but there are many differences in these basic similarities. There is no water on the surface of Venus and there is no water in the air. The main component of its cloud is sulfuric acid, which is much higher than the height of the earth cloud. Due to the high atmospheric pressure, the wind speed on Venus is relatively slow. In other words, the surface of Venus is neither affected by wind nor washed by rain. Therefore, the volcanic characteristics of Venus can obviously be maintained for a long time.

Venus has no plate structure, no linear volcanic chain and no obvious plate extinction zone. Although Venus is a crisscross canyon, there is no trench like the earth.

There are indications that the eruption form of Venus volcano is also relatively simple. Solidification geological structure

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.

Scientists speculate that the internal structure of Venus may be similar to that of the Earth. According to the structure of the earth, the main components of Venus mantle are silicates dominated by olivine and pyroxene, and a crust dominated by silicates, the core of which is composed of iron-nickel alloy. The average density of Venus is 5.24g/cc, which is the third among the nine planets, second only to Earth and Mercury.

An iron core with a diameter of 3,000 kilometers, molten stones filled most of the planets to form the mantle. Recent gravity data from Magellan show that Venus' shell is much harder and thicker than previously assumed. Like the earth, convection in the mantle exerts pressure on the surface, but it reduces the load through many relatively small areas, so that it will not be destroyed at the plate boundary like the earth.

Saturn (Saturn)

The orbit is 654.38+0.4294 million kilometers away from the sun and 654.38+0.0759.5 days away from the period of revolution, which is equivalent to 29.5 Earth years with an apparent magnitude of 0.67. Among the planets in the solar system, Saturn's halo is the most striking, which makes Saturn look like wearing a beautiful straw hat. Observations show that the substances that make up the halo are crushed ice, rocks, dust, particles and so on. They are arranged in a series of circles and revolve around Saturn.

Saturn is like Jupiter in many ways. For example, it is a giant planet with a volume of 745 times that of the Earth and a mass of 95. 18 times that of the Earth. Among the nine planets in the solar system, Saturn is second only to Jupiter in size and mass. Like Jupiter, it is surrounded by colorful clouds and guarded by more satellites. It is oblate because it rotates very fast. The equatorial radius is about 60,000 kilometers. The average density of Saturn is only 0.70g/cm ~ 3, which is the lowest among the eight planets. If you put it in water, it will float on the water. Saturn's large radius and low density make its surface gravity acceleration close to that of the earth. Saturn's brightness when it hits the sun can be compared with that of the brightest star in the sky. Because the plane of the halo does not coincide with Saturn's orbital plane, and the direction of the halo plane is unchanged when it runs around the sun, the apparent area of the halo is not fixed from the earth, so the apparent brightness of Saturn also changes. When the visible area of Saturn's rings is the largest, Saturn appears brighter; When the line of sight coincides with the plane of the halo, the halo appears as a straight line, and Saturn appears darker. The brightness difference between them is about 3 times.

Saturn's orbit around the sun has a radius of about 65.438+0.4 billion kilometers, and its orbit is oval. Its distance from the sun is about1.500 million kilometers at perihelion and apohelion. The average speed of Saturn's revolution around the sun is about 9.64 kilometers per second, and its period of revolution is about 29.5 years. Saturn also has four seasons, but each season lasts for more than seven years, because it is far from the sun, and it is extremely cold even in summer. Saturn's rotation speed is very fast, but the rotation speed at different latitudes is different, which is greater than Jupiter's. The rotation period on the equator is 18 hours 14 minutes, which becomes 10 hour and 40 minutes at 60 degrees latitude. That is to say, on Saturn's equator, there are only 10 hours and 14 minutes in a day and night.

Saturn is green near the polar regions, which is the darkest area on the whole surface. According to infrared observation, cloud top temperature is-170℃, which is 50℃ lower than Jupiter. Saturn's surface temperature is about-140℃. White spots sometimes appear on Saturn's surface. The most famous white spot was found in August 1933. This white spot appears in the equatorial region, which is egg-shaped and reaches 1/5 of Saturn's diameter. After that, the white spot continued to expand and almost spread to the entire equatorial belt.

Due to the low surface temperature and high escape speed (35.6 km/s), Saturn retained all the hydrogen and helium when it was formed billions of years ago. Therefore, scientists believe that studying the current composition of Saturn is equivalent to studying the original composition of the early solar system, which is very helpful for understanding the internal activities and evolution of the sun. It is generally believed that Saturn's chemical composition is similar to Jupiter's, but its hydrogen content is less. Saturn has more methane than Jupiter, but less ammonia.

At present, it is believed that when Saturn was formed, it was initially the accretion of soil and ice, followed by the accumulation of gas. So Saturn has a core with a diameter of 20,000 kilometers. This core accounts for 10% to 20% of Saturn's mass. The core is surrounded by an ice shell with a thickness of 5,000 kilometers and a metal hydrogen layer with a thickness of 8,000 kilometers. In addition to metallic hydrogen, there is an extensive molecular hydrogen layer.

Saturn's interior is similar to Jupiter's, with a rock core. Outside the core is a shell composed of 5000 kilometers of ice and 8000 kilometers of metallic hydrogen, and the outermost layer is surrounded by colorful clouds. Saturn's atmospheric movement is relatively calm, and its surface temperature is very low, about-140 degrees Celsius.

Saturn rotates obliquely around the sun at an average speed of 9.64 kilometers per second. Its orbit radius is about 65.438+0.4 billion kilometers, and its revolution speed is slow. It takes 29.5 years to go around the sun, but the rotation speed is very fast. The rotation period on the equator is 654.38+00 hours and 654.38+04 minutes.

Lighter than water.

Saturn, like other planets, orbits the sun in an elliptical orbit. Saturn's orbital radius around the sun is about 9.54 astronomical distance units (about 65.438+0.4 billion kilometers), the orbital eccentricity is 0.056, the included angle between the orbital plane and the ecliptic plane is 2.5', it takes about 29.5 years to orbit the sun, and the average revolution speed is about 9.6 kilometers per second. Saturn's rotation speed is very fast, second only to Jupiter, and its rotation speed varies with latitude. The rotation period on the equator is 10 hour 14 minutes, and at latitude 60, it is 10 hour and 40 minutes. Because of its rapid rotation, its shape is flattened, which makes it the flattest in planets of the solar system. Saturn's surface also has stripes extending along the equator, and its surface is covered by clouds.

Orbit long radius (astronomical distance unit) 9.539

Track long radius (ten million kilometers) 1427.0

Constant Week of Revolution (Japan) 10759.5

The rendezvous period of revolution (days) 378

Track eccentricity 0.056

Track inclination (degree) 2.5

Ascending meridian (degree) 1 13.3

Perihelion longitude (degree) 92.3

Average track speed (km) 9.64

Equatorial radius (km) 60330

Flatness 0. 102

Mass (Earth mass = 1) 95. 159

Density (g/cm3) 0.70

Equatorial gravity (Earth = 1) 1.08

Escape speed (km/s) 35.6

Rotation period (days) 0.426

The intersection of yellow and red (degree) is 26.73.

Albedo 0.57

Maximum brightness -0.4

Number of satellites (confirmed) 23

Jupiter data

Orbit: 778,330,000 kilometers (5.20 astronomical units) from the sun.

Planet diameter: 142984 km (equator)

Mass: 1.90 * 10 27kg

Jupiter is the fourth brightest object in the sky (second only to the sun, the moon and Venus; Sometimes Mars is brighter), Jupiter has been known to mankind as early as prehistoric times. According to Galileo's observation of Jupiter's four moons: Io, Europa, Ganymede and Callisto (now often called Galileo's moons) in 16 10, it was the first time that they were found not to orbit the earth, and it was also the main basis for agreeing with Copernicus's Heliocentrism about planetary motion.

The gaseous planet has no solid surface, and the density of gaseous matter only increases with the increase of depth (we calculate its radius and diameter from the point where its surface is equivalent to 1 atmosphere). What we usually see is the cloud top in the atmosphere, and the air pressure is slightly higher than 1 atmospheric pressure.

The information we obtained about Jupiter's internal structure (and other gaseous planets) came from indirect sources and remained stagnant for a long time. (Galileo's Jupiter atmospheric data only detected150km below the clouds. )

Jupiter may have a rock core, which is equivalent to the mass of 10- 15 earths.

In the inner core, most planetary materials are concentrated in the form of liquid hydrogen. These most common formal foundations on Jupiter may only exist under the pressure of 4 billion bar, which is the internal environment of Jupiter (and Saturn). Liquid metallic hydrogen consists of ionized protons and electrons (similar to the interior of the sun, but at a much lower temperature). Under the temperature and pressure inside Jupiter, hydrogen is liquid, not gaseous, which makes it the electron director and source of Jupiter's magnetic field. This layer may also contain some helium and some ice.

The outermost layer is mainly composed of ordinary hydrogen and helium molecules, with liquid inside and vaporized outside. What we can see is the higher part of this deep layer. Water, carbon dioxide, methane and other simple gas molecules are also rare here.

The atmospheric data from Galileo also proved that there was much less water there than expected. At first, it was estimated that the oxygen content in Jupiter's atmosphere was twice that of the current sun (including enough hydrogen to generate water), but at present its concentration is actually lower than that of the sun. Another surprising news is the high temperature and density of the outer atmosphere.

Is the alternate "Sun" Jupiter just a planet? Why can't it be regarded as a future star and a celestial body developing in the direction of a star? Readers may be surprised: is it ridiculous to ask questions like this? In the early 1980s, Soviet scientist Su Chekhov put forward a new idea that Jupiter might be a developing star, and it did meet with a lot of criticism. However, Suchikov's view is not a castle in the air and has no basis. His main point is: Jupiter is undergoing thermonuclear reaction, which has its own thermonuclear energy and should be classified as a star-like object, which can generate heat and glow by itself.

Jupiter is much farther away from the sun than the earth and receives much less solar radiation, so the surface temperature is naturally much lower. According to the calculation results, the surface temperature of Jupiter should be-168 degrees Celsius. However, the temperature observed on the ground is-139 degrees Celsius, which is nearly 30 degrees Celsius different from the calculated value. In any case, it cannot be caused by error. It should be more accurate to let the probe measure near Jupiter. When Xianfeng 1 1 flew past Jupiter in February, 1974, the measured surface temperature of Jupiter was-148 degrees Celsius, which was still far higher than the theoretical value, indicating that Jupiter had its own internal heat source. Jupiter is a celestial body with hydrogen as the main component, which is very different from our earth and similar to the sun. The atmospheres of Jupiter and the sun both contain about 90% hydrogen and about 10% helium, and a small amount of other gases. As for the internal structure of Jupiter, the model established now thinks that its surface is not solid, and the whole planet is in a fluid state. The central part of Jupiter is likely to be a solid core, mainly composed of iron and silicon, where the temperature can reach at least 30,000 degrees. There are two layers of hydrogen outside the nucleus, one is liquid metal hydrogen and the other is liquid molecular hydrogen. These two layers are collectively called Jupiter mantle. Further up, hydrogen becomes the main component of the atmosphere in gaseous state.