10 What is the sign of the person born in April? Where is Venus?

Venus is one of the eight planets in the solar system, and it is the second planet in the order from near to far from the sun. It is the closest planet to the earth. China called it Taibai or Taibai Venus in ancient times. It is sometimes the morning star, which appears in the eastern sky before dawn and is called "Qi Ming". Sometimes it is a dim star, which appears in the western sky after dusk and is called Chang Gung. Venus is the brightest star except the sun and the moon in the whole day, with the maximum brightness of -4.4, which is 14 times brighter than the famous Sirius (the brightest star except the sun in the whole day), like a dazzling diamond, so the ancient Greeks called it Aphrodite, the goddess of love and beauty, while the Romans called it Venus, the god of beauty.

Venus, like Mercury, is the only two big planets in the solar system without natural satellites. So there is no "moon" in the night sky on Venus, and the brightest "star" is the earth. Because it is close to the sun, the size of the sun seen from Venus is 1.5 times larger than that seen from the earth.

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.

There is a dense atmosphere and clouds around Venus. These clouds cast a mysterious veil on the surface of Venus. Only with the help of radio telescopes can we cross this atmosphere and see the true face of Venus. In the atmosphere of Venus, carbon dioxide is the most, accounting for more than 97%. At the same time, there is a layer of concentrated sulfuric acid with a thickness of 20 to 30 kilometers. The surface temperature of Venus is as high as 465 to 485 degrees, and the atmospheric pressure is about 90 times that of the Earth.

Venus's rotation is very special. It is the only big planet in the solar system that rotates in the opposite direction. Its rotation direction is opposite to that of other planets, from east to west. Therefore, on Venus, the sun rises in the west and sets in the east. Venus's orbit around the sun is an ellipse that is very close to a perfect circle and coincides with the ecliptic plane. Its revolution speed is about 35 kilometers per second, and that of period of revolution is about 224.70 days. But its rotation period is 243 days, which means that Venus' rotation sidereal day is getting longer every day. However, according to the earth's standards, if one day is counted from one sunrise to the next, one day on Venus is far less than 243 days. This is because Venus rotates in the opposite direction; On Venus, the sunrise is in the west and the sunset is in the east. The alternation of day and night from one sunrise to the next is only 1 16.75 days on earth.

Venus reversal may have been caused by Venus colliding with other asteroids a long time ago, but it has not been confirmed 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.

Astral data

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)

Surface area: 460 million square kilometers

Surface gravity acceleration: 8.78m/s2.

Turnaround time: 243.02 days

Escape speed:10.4km/s.

Mass: 4.67e24kg

Surface temperature: The lowest, average and highest temperatures are 737K, 750K and 773K respectively.

topography

There are two main continental highlands on the great plains on the surface of Venus. The highland in the north is called Ishtar Terra, where there is Maxwell Mountain (about two kilometers higher than the Himalayas) with the highest Venus. It was named after james clerk maxwell. The Maxwell Mountains surround the Laxmi Plateau. Istar is about the size of Australia. In the southern hemisphere, there is a larger Terra in Aphrodite, the size of South America. There are many vast lowlands between these highlands, including Atlanta Plain, Guinevere Plain and 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). At that time, a wide range of mountain fires scrubbed the early surface, including several large craters formed in the early history of Venus. 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. A grand canyon 1200 kilometers long, which runs through the equator from south to north, is the largest canyon among the eight planets.

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.

Data from Magellan Aircraft Imaging Radar show that most of the surface of Venus is covered by lava flows. There are several large shielded volcanoes, such as Sif Mons (right), similar to Mount Olympus in Hawaii and Mars. The recently published discovery data show that the volcanic activity of Venus is still very active, but it is concentrated in several hot spots; The terrain in most areas has been formed, which is much quieter than in the past hundreds of millions of years.

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.