The universe is huge. Scientists trying to embrace it in their research often feel the incomparable loneliness of humanity that permeates some of Efremov’s novels. There is too little chance of discovering life like ours in accessible space.
For a long time, among the candidates for occupation by organic life was solar system, shrouded in legends no less than in fog.
Venus, in terms of distance from the star, immediately follows Mercury and is our closest neighbor. From Earth it can be seen without the help of a telescope: in the evening and predawn hours, Venus is the brightest in the sky after the Moon and the Sun. The color of the planet for a simple observer is always white.
In literature you can find it referred to as the Earth's twin. There are a number of explanations for this: the description of the planet Venus in many respects repeats the data about our home. First of all, these include the diameter (about 12,100 km), which practically coincides with the corresponding characteristic of the Blue Planet (a difference of about 5%). The mass of the object, named after the goddess of love, also differs little from that of the earth. Proximity also played a role in partial identification.
The discovery of the atmosphere reinforced the opinion about the similarity of the two. Information about the planet Venus, confirming the presence of a special air shell, was obtained by M.V. Lomonosov in 1761. A brilliant scientist observed the passage of the planet across the disk of the Sun and noticed a special glow. The phenomenon was explained by the refraction of light rays in the atmosphere. However, subsequent discoveries revealed a huge gap between the seemingly similar conditions on the two planets.
Veil of secrecy
Evidence of similarity, such as Venus and the presence of its atmosphere, was supplemented by data on the composition of the air, which effectively crossed out dreams of the existence of life on the Morning Star. In the process they were discovered carbon dioxide and nitrogen. Their share in air envelope distributed respectively as 96 and 3%.
The density of the atmosphere is a factor that makes Venus so clearly visible from Earth and at the same time inaccessible to research. The layers of clouds that shroud the planet reflect light well, but are opaque to scientists who want to determine what they hide. More detailed information about the planet Venus became available only after the start of space research.
The composition of the cloud cover is not fully understood. Presumably, sulfuric acid vapor plays a large role in it. The concentration of gases and the density of the atmosphere, approximately one hundred times higher than on Earth, creates a greenhouse effect on the surface.
Eternal heat
The weather on the planet Venus is in many ways similar to fantastic descriptions of conditions in the underworld. Due to the peculiarities of the atmosphere, the surface never cools even from that part that is turned away from the Sun. And this despite the fact that the Morning Star makes a revolution around its axis in more than 243 Earth days! The temperature on the planet Venus is +470ºC.
The absence of a change of seasons is explained by the tilt of the planet’s axis, which, according to various sources, does not exceed 40 or 10º. Moreover, the thermometer here shows same results both for the equatorial zone and for the polar region.
Greenhouse effect
Such conditions leave no chance for water. According to researchers, Venus once had oceans, but rising temperatures made their existence impossible. Ironically, education greenhouse effect became possible precisely due to the evaporation of a large amount of water. Steam leaks sunlight, but retains heat at the surface, thereby contributing to an increase in temperature.
Surface
The heat also contributed to the formation of the landscape. Before the advent of radar methods in the arsenal of astronomy, the nature of the surface of the planet Venus was hidden from scientists. Photos and images taken helped to compose quite detailed map relief.
High temperatures have thinned the planet's crust, so here big number volcanoes, both active and extinct. They give Venus that hilly appearance that is clearly visible in radar images. Flows of basaltic lava have formed vast plains, against which hills stretching over several tens of square kilometers are clearly visible. These are the so-called continents, comparable in size to Australia, and in the nature of the terrain reminiscent of the mountain ranges of Tibet. Their surface is dotted with cracks and craters, in contrast to the landscape of part of the plains, which is almost completely smooth.
There are much fewer craters left by meteorites here than, for example, on the Moon. Scientists name two possible reasons this: a dense atmosphere that plays the role of a kind of screen, and active processes, erasing traces of falling cosmic bodies. In the first case, the discovered craters most likely appeared during a period when the atmosphere was more rarefied.
Desert
The description of the planet Venus will be incomplete if we pay attention only to radar data. They give an idea of the nature of the relief, but it is difficult for the average person to understand on their basis what he would see if he got here. Studies of spacecraft landing on the Morning Star helped answer the question of what color the planet Venus would appear to an observer on its surface. As befits a hellish landscape, shades of orange and gray dominate here. The landscape really resembles a desert, waterless and bursting with heat. Such is Venus. The color of the planet, characteristic of the soil, dominates the sky. The reason for such an unusual color is the absorption of the short-wavelength part of the light spectrum, characteristic of a dense atmosphere.
Learning Difficulties
Data about Venus is collected by devices with great difficulty. Staying on the planet is complicated by strong winds, reaching their peak speed at an altitude of 50 km above the surface. Near the ground, the elements calm down to a large extent, but even weak air movement is a significant obstacle in the dense atmosphere that the planet Venus has. Photos that give an idea of the surface are taken by ships that can only withstand a hostile onslaught for a few hours. However, there are enough of them that after each expedition scientists discover something new for themselves.
Hurricane winds are not the only feature that the weather on the planet Venus is famous for. Thunderstorms rage here with a frequency exceeding the same parameter for the Earth twice as much. During periods of increasing activity, lightning causes a specific glow in the atmosphere.
"Eccentricities" of the Morning Star
The Venusian wind is the reason why the clouds move around the planet much faster than the planet itself around its axis. As noted, the latter parameter is 243 days. The atmosphere sweeps around the planet in four days. The Venusian quirks don't end there.
The length of the year here is slightly less than the length of the day: 225 Earth days. At the same time, the Sun on the planet rises not in the east, but in the west. Such an unconventional direction of rotation is characteristic only of Uranus. It was the speed of rotation around the Sun that exceeded the Earth's speed that made it possible to observe Venus twice during the day: in the morning and in the evening.
The planet's orbit is almost a perfect circle, and the same can be said about its shape. The Earth is slightly flattened at the poles; the Morning Star does not have this feature.
Coloring
What color is the planet Venus? Partially this topic has already been covered, but not everything is so clear. This characteristic can also be considered one of the features that Venus possesses. The color of the planet, when viewed from space, differs from the dusty orange inherent in the surface. Again, it’s all about the atmosphere: the veil of clouds does not let the rays of the blue-green spectrum pass below and at the same time colors the planet for an outside observer in a dirty white. For earthlings, rising above the horizon, the Morning Star has a cold shine, and not a reddish glow.
Structure
Numerous spacecraft missions have made it possible to draw not only conclusions about the color of the surface, but also to study in more detail what is underneath it. The structure of the planet is similar to that of Earth. The morning star has a crust (about 16 km thick), a mantle underneath and a core - the core. The size of the planet Venus is close to that of Earth, but the ratio inner shells hers is different. The thickness of the mantle layer is more than three thousand kilometers; its basis is various silicon compounds. The mantle surrounds a relatively small core, liquid and predominantly iron. Significantly inferior to the earthly “heart,” it makes a significant contribution to approximately a quarter of it.
Features of the planet's core deprive it of its own magnetic field. As a result, Venus is exposed to the solar wind and is not protected from the so-called hot flow anomaly, explosions of colossal magnitude that occur frighteningly often and could, according to researchers, absorb the Morning Star.
Exploring the Earth
All the characteristics that Venus has: the color of the planet, the greenhouse effect, the movement of magma, and so on, are being studied, including with the aim of applying the data obtained to our planet. It is believed that the structure of the surface of the second planet from the Sun can give an idea of what the young Earth looked like about 4 billion years ago.
Data on atmospheric gases tell researchers about the time when Venus was just forming. They are also used in constructing theories about the development of the Blue Planet.
For a number of scientists, the scorching heat and lack of water on Venus seem to be a possible future for the Earth.
Artificial cultivation of life
Projects to populate other planets with organic life are also associated with forecasts promising the death of the Earth. One of the candidates is Venus. The ambitious plan is to spread blue-green algae in the atmosphere and on the surface, which is a central link in the theory of the origin of life on our planet. Delivered microorganisms, in theory, can significantly reduce the level of carbon dioxide concentration and lead to a decrease in pressure on the planet, after which further settlement of the planet will become possible. The only insurmountable obstacle to the implementation of the plan is the lack of water necessary for the algae to flourish.
Certain hopes in this matter are pinned on some types of mold, but so far all developments remain at the level of theory, since sooner or later they encounter significant difficulties.
Venus is a truly mysterious planet in the solar system. The research carried out answered a lot of questions related to it, and at the same time gave rise to new ones, in some ways even more complex. The morning star is one of the few cosmic bodies bearing a female name, and, like beautiful girl, it attracts glances, occupies the thoughts of scientists, and therefore there is a high probability that researchers will still tell us a lot of interesting things about our neighbor.
The second planet from the Sun, Venus, is the closest to Earth and, perhaps, the most beautiful of the terrestrial planets. For thousands of years she has attracted curious glances from scientists of ancient and modern times to mere mortal poets. No wonder she bears the name of the Greek goddess of love. But its study rather adds questions than gives any answers.
One of the first observers, Galileo Galilei, observed Venus using spyglass. With the advent of more powerful optical devices such as telescopes in 1610, people began to note the phases of Venus, which closely resembled lunar phases. Venus is one of the brightest stars in our sky, so at dusk and in the morning, you can see the planet with the naked eye. Watching its passage in front of the Sun, Mikhailo Lomonosov in 1761 examined a thin rainbow rim surrounding the planet. This is how the atmosphere was discovered. It turned out to be very powerful: the pressure near the surface reached 90 atmospheres!
The greenhouse effect explains high values temperatures of the lower layers of the atmosphere. It is also present on other planets, for example on Mars, due to it, the temperature can rise by 9°, on Earth - up to 35°, and on Venus - it reaches its maximum, among planets - up to 480° C.
Internal structure of Venus
The structure of Venus, our neighbor, is similar to other planets. It includes the crust, mantle and core. The radius of the liquid core containing a lot of iron is approximately 3200 km. The structure of the mantle - molten matter - is 2800 km, and the thickness of the crust is 20 km. It is surprising that with such a core, the magnetic field is practically absent. This is most likely due to the slow rotation. The atmosphere of Venus reaches 5500 km, the upper layers of which consist almost entirely of hydrogen. The Soviet automatic interplanetary stations (AMS) Venera-15 and Venera-16 back in 1983 discovered mountain peaks with lava flows on Venus. Now the number of volcanic objects reaches 1600 pieces. Volcanic eruptions indicate activity in the planet's interior, which is locked under thick layers of basalt shell.
Rotation around its own axis
Most of the planets in the solar system rotate around their axis from west to east. Venus, like Uranus, is an exception to this rule, and rotates in the opposite direction, from east to west. This non-standard rotation is called retrograde. Thus, a full revolution around its axis lasts 243 days.
Scientists believe that after the formation of Venus, there was a large number of water. But, with the advent of the greenhouse effect, the evaporation of the seas began and the release of carbon dioxide anhydrite, which is part of various rocks, into the atmosphere. This led to an increase in water evaporation and an overall increase in temperature. After some time, the water disappeared from the surface of Venus and entered the atmosphere.
Now, the surface of Venus looks like a rocky desert, with occasional mountains and undulating plains. From the oceans, only huge depressions remained on the planet. Radar data taken from interplanetary stations recorded traces of recent volcanic activity.
In addition to the Soviet spacecraft, the American Magellan also visited Venus. He produced an almost complete mapping of the planet. During the scanning process, a huge number of volcanoes, hundreds of craters and numerous mountains were discovered. Based on their characteristic elevations, relative to the average level, scientists have identified 2 continents - the land of Aphrodite and the land of Ishtar. On the first continent, the size of Africa, there is an 8-kilometer Mount Maat - a huge extinct volcano. The continent of Ishtar is comparable in size to the United States. Its attraction is the 11-kilometer Maxwell Mountains, the highest peaks on the planet. Compound rocks, resembles terrestrial basalt.
On the Venusian landscape, impact craters filled with lava can be found with a diameter of about 40 km. But this is an exception, because there are about 1 thousand of them in total.
Characteristics of Venus
Weight: 4.87*1024 kg (0.815 earth)
Diameter at the equator: 12102 km
Axle tilt: 177.36°
Density: 5.24 g/cm3
Average surface temperature: +465 °C
Period of rotation around the axis (days): 244 days (retrograde)
Distance from the Sun (average): 0.72 a. e. or 108 million km
Orbital period around the Sun (year): 225 days
Orbital speed: 35 km/s
Orbital eccentricity: e = 0.0068
Orbital inclination to the ecliptic: i = 3.86°
Acceleration free fall: 8.87m/s2
Atmosphere: carbon dioxide (96%), nitrogen (3.4%)
Satellites: no
Venus is the second planet from the Sun, the closest planet to Earth, and the third brightest object in the sky after the Sun and Moon. Sometimes this planet is called the sister of the Earth, which is due to a certain similarity in mass and size. The difference in diameters of the Earth and Venus is 638 km, and the mass of Venus reaches 81.5% of the Earth's. The planet Venus is covered by an impenetrable layer of clouds filled mainly with sulfuric acid.
The planet received this well-known name in honor of the Roman goddess of love and beauty. The planet Venus is very noticeable in the sky due to its high brightness, so it has been noticed for a long time. Most likely, the brightness and visibility of Venus played a role in the fact that she was named after the goddess of love. So she is associated with love, femininity and romance.
Venus is the second planet from the Sun, but the hottest planet in the Solar System.
The length of the day on Venus, i.e. one full revolution around its axis lasts longer than one Venusian year. One axial revolution of the planet takes 244 days, and the orbital path (year) takes 225 days.
Atmospheric pressure is 92 times greater than on Earth.
Venus Research
Several spaceships have already flown to Venus. The first of them, Venera 1, only flew past Venus. Venera-1 is a Russian spacecraft, developed by the Energia rocket and space corporation named after S.P. Korolev (today NPO Energia). The flight of Venera 1 was unsuccessful because communication with the ship was lost. There were other unsuccessful flights. But there were also ships that could not only study chemical composition atmosphere, but also even reach the surface itself.
The first ship that was able to conduct atmospheric research was Venera 4. It was launched on June 12, 1967. The mission of Venera 4 was short - the descent module was literally crushed by pressure in the planet's atmosphere, but the orbital module managed to carry out a number of valuable observations and obtain the first data about Venus. This expedition made it possible to determine that the planet's atmosphere consists of 90% carbon dioxide with a small content of oxygen and water vapor.
Atmosphere of Venus
The atmosphere of the planet Venus is divided into several high-altitude layers: the troposphere, stratosphere, mesosphere, and thermosphere. Above 700 km from the surface, the corona of Venus begins, which consists only of hydrogen and smoothly passes into interplanetary space.
The stratosphere occupies space at an altitude of 70 to 90 km. She's pretty dressed up.
At an altitude of 50-70 km there is a main cloud layer that covers the entire planet in an impenetrable sphere.
At 30-50 km there is sub-block haze. 
The opacity of the atmosphere of Venus is explained not so much by mass or very high density gaseous shell, as mainly permanently closed by a layer of clouds. The main component of the cloud layer is droplets of sulfuric acid, the content of which reaches approximately 75 mass percent. In addition, chlorine- and phosphorus-containing aerosols are also present here. The lower of the three layers of clouds may also contain traces of elemental sulfur.
Larger droplets of sulfuric acid fall as rain, falling just short of the lower edge of the cloud layer, where they evaporate under the influence of high temperatures and then break down into sulfur dioxide, water vapor and oxygen. Once these gases rise to the very top of the clouds, they react and condense there again as sulfuric acid. Sulfur in clouds originally appeared in the form of sulfur dioxide during volcanic eruptions.
Clouds surround Venus in a layer from 50 to 80 kilometers above the surface of the planet and consist mainly of sulfur dioxide (SO2) and sulfuric acid (H2SO4). These clouds are so dense that they reflect back into space 60% of all the light from the Sun that shines on Venus.
A greenhouse effect is created, and the temperature of the layer can reach 480°C, which allows the surface of Venus to be heated to the maximum temperatures in our system.
The atmospheric pressure at the surface of Venus is 90 times greater than on Earth. That's why for a long time It was not possible to bring the descent vehicle to the surface of the planet - they were crushed by monstrous pressure.
But people kept sending new devices
The Mariner 10 spacecraft flew by Venus at an altitude of 4000 km in 1967. He received information about the pressure, atmospheric density and composition of the planet.
In 1969, the Soviet Venera 5 and 6 also arrived, which managed to transmit data during 50 minutes of descent. But Soviet scientists did not give up. Venera 7 crashed on the surface, but transmitted 23 minutes of information.
From 1972-1975 The USSR launched three more probes, which managed to obtain the first images of the surface.
Over 4,000 pictures along the way Mercury received Mariner 10. In the late 70s of the 20th century, NASA prepared two probes. One of them was to study the atmosphere and create a surface map, and the second was to enter the atmosphere.
In 1985, the Vega program was launched, where the devices were supposed to explore Halley's comet and go to Venus. They dropped probes, but the atmosphere turned out to be more turbulent and the mechanisms were blown away by powerful winds.
In 1989, Magellan went to Venus with his radar. It spent 4.5 years in orbit and imaged 98% of the surface and 95% of the gravitational field. In the end, it was sent into the atmosphere, where it burned up, but received density data.
Venus was observed in passing by the Galileo and Cassini spacecraft. And in 2007 they sent MESSENGER, which was able to make some measurements on the way to Mercury. The atmosphere and clouds were also monitored by the Venus Express probe in 2006. The mission ended in 2014.
Geology of Venus
Like other terrestrial planets, the planet Venus consists of three layers: crust, mantle and core. It is believed that the interior of Venus (unlike Mercury or Mars) is very similar to the interior of the Earth. Due to the fact that it is not yet possible to compare full-fledged geological studies (field work, so to speak), the true composition of the layers of the planet has not yet been established. On this moment Venus's crust is thought to be 50 kilometers thick, its mantle 3,000 kilometers thick, and its core 6,000 kilometers in diameter.
Among the Slavs, Venus was called Zarya-Mertsana
However, some studies indicate that Venus's core is solid. To prove this theory, researchers cite the fact that the planet significantly lacks a magnetic field. Simply put, planetary magnetic fields result from the transfer of heat from inside a planet to its surface, and a necessary component of this transfer is the liquid core. The insufficient strength of magnetic fields, according to this concept, indicates that the existence of a liquid core on Venus is simply impossible.
Orbit and rotation of Venus
The most remarkable aspect of Venus's orbit is its uniform distance from the Sun. The orbital eccentricity is only .00678, that is orbit Venus is the roundest of all the planets in the solar system. Moreover, such a small eccentricity indicates that the difference between Venus's perihelion (1.09 x 10 8 km) and its aphelion (1.09 x 10 8 km) is only 1.46 x 10 6 kilometers.
Information about the rotation of Venus, as well as data about its surface, remained a mystery until the second half of the twentieth century, when the first radar data were obtained. It turned out that the planet's rotation around its axis is counterclockwise when viewed from the "upper" plane of the orbit, but in fact Venus's rotation is retrograde, or clockwise. The reason for this is currently unknown.
Billions of years ago, Venus' climate may have been similar to Earth's. Scientists believe Venus once had abundant water and oceans, but high temperatures and the greenhouse effect have boiled away the water and the planet's surface is now too hot and hostile to support life.
Characteristics of Venus briefly
Weight: 4.87*10¬24 kg (0.815 earth)
Diameter at the equator: 12102 km
Axle tilt: 177.36°
Density: 5.24 g/cm3
Average surface temperature: +465 °C
Period of rotation around the axis (days): 244 days (retrograde)
Distance from the Sun (average): 0.72 a. e. or 108 million km
Orbital period around the Sun (year): 225 days
Orbital speed: 35 km/s
Orbital eccentricity: e = 0.0068
Orbital inclination to the ecliptic: i = 3.86°
Gravity acceleration: 8.87m/s2
Atmosphere: carbon dioxide (96%), nitrogen (3.4%)
Satellites: no
Of all the planets in the solar system Venus in size and structure it is most similar to the Earth. With a diameter of 12,100 km, it is the “twin” of our planet. But despite this proximity, it is unlikely that astronauts will ever be able to land on its surface. Extremely heat and the dense atmosphere do not allow a person to stay there even for a short time.
Venus has its own, very special, characteristics in the solar system. Of all the planets, Venus is the only one, except Uranus, that rotates on its axis from east to west. Typically, planets rotate around their axis in the same direction in which they revolve around the Sun, that is, from west to east. Astronomers call the “reverse” rotation of Venus retrograde.
In addition, the rotation period of the planet Venus is quite long, noticeably longer than the orbital period. It takes Venus 243 days to complete a full rotation on its axis, but only 225 days to complete its almost perfectly circular solar orbit.
This means that, unlike the Earth, whose rotation determines the cycle of day and night, on Venus the period when the Sun remains above the horizon depends on the planet’s orbital period around the luminary.
Structure of Venus
The internal structure of Venus is thought to be similar to that of Earth, with a crust, a mantle of molten materials, and a ferruginous inner core. According to the current model, the thickness of the core is 3200 km, the mantle is 2800 km, and the crust is 20 km.The iron core, it would seem, should generate a magnetic field; in fact, it is absent, apparently due to the peculiarities of the planet’s movement. The slow rotation of the planet is an explanation for this phenomenon, although not entirely convincing.
But the solar wind, when it breaks through the upper layers of the atmosphere, ionizes them and forms an atmospheric front, creating an elongated magnetic field, elongated in the direction opposite to the direction of the solar wind.
Atmosphere of Venus
Carbon dioxide makes up 96.5% of the total atmosphere, the remaining 3.5% is nitrogen with traces of oxygen, carbon monoxide, argon and sulfuric anhydride. In addition, there is a low percentage of water vapor.Perhaps, in the first phases of the Earth's evolution, its atmosphere was similar to that of Venus. Due to the fact that the substances that make up the Venusian atmosphere are very heavy, the pressure on the surface of the planet is much greater than that on Earth. atmospheric pressure. It is close to the value that exists on Earth at a depth of 90 m under water - 90-95 atmospheres. An astronaut on Venus would be subjected to this terrible force, which would immediately flatten him. And the gas mixture is also toxic to humans.
The increased density and special composition of the atmosphere cause a very powerful greenhouse effect. The lower layers of the atmosphere retain heat in the same way as heat is retained in a greenhouse. As a result, the temperature reaches 475°C.
Modules launched from the probes detected the presence of strong radio waves emitted by electrical currents, which clearly indicates that there are thunderstorms on Venus, much stronger and more frequent than on Earth.
Observations of the atmosphere of Venus have shown the presence of strong winds in the upper layers. In these layers, clouds in retrograde motion make a full revolution around the planet in four days, while its rotation around its axis is 243 days. As altitude increases, temperature decreases. For example, at an altitude of 100 km it is -90 °C.
Venus likely had oceans of water on its surface shortly after its formation. But as time passed, the radiation from the Sun (then still very young) was too strong, and the oceans began to evaporate, and carbon dioxide was released from the rocky soil and spread into the atmosphere. Over time, the greenhouse effect intensified and the temperature continued to rise, increasing evaporation. Soon all the water disappeared from the surface, and the carbon dioxide content in the atmosphere became very high. 
A computer simulation of a view of Venus without clouds (left) and a composite radar image of the same hemisphere (right), obtained during the Magellan mission. Center of frame - 180 degrees east longitude (NASA/USGS illustration)
Surface of Venus
The surface of Venus is a rocky desert illuminated with yellowish light, dominated by orange and brown colors soil. In the absence of seas, orographic features (mountains or lowlands) can be determined; they have stabilized at an average level, although there are high mountain zones. The relief includes hills, plains and small mountain ranges. There are also lowlands on the site of the planet's prehistoric oceans.With the help of probes, especially Magellan, it was discovered that volcanic activity takes place on Venus. This conclusion was made based on scans of some areas, which showed the presence of surface opacity, indicating the presence of recently erupted lava. Indeed, under the influence of the dense atmosphere of the planet, the surface part of the magma very quickly undergoes erosion, revealing a layer of iron sulfide, which reflects radar rays very well, since it is a good conductor.
The composition of Venusian rocks is similar to that of terrestrial basalt rocks. At the same time, the morphology and results of tectonic activity (craters, volcanoes, meteorite falls, earthquakes) are so diverse that one can assume a very rich and turbulent geological history.
On Venus, two areas suggestive of continents can be distinguished because they are located at a significant altitude above the average surface level. These regions, the Land of Ishtar and the Land of Aphrodite, are respectively in the Northern Hemisphere and south of the equator, which intersects the Land of Aphrodite in its northern part.
The land of Ishtar is slightly smaller in size than the United States, and is dominated by the most high peak planets, Mount Maxwell, 11 km high.
The land of Aphrodite is slightly larger than Africa. There is Mount Maat, an 8 km high volcano surrounded by a plain of freshly erupted lava, indicating the presence of volcanic activity on Venus. On this continent there is a system of canyons of tectonic origin, stretching for hundreds of kilometers, 2-4 km deep and up to 280 km wide.
Characteristics of Venus
Average distance from the Sun - 108.2 million km (minimum - 107.4; maximum - 109)Equatorial diameter - 12,103 km
The average speed of orbital motion around the Sun is 35.03 km/s
Rotation period - 243 days 00 hours 14 minutes (retrograde)
Circulation period - 224.7 days
Known satellites - none
Mass (Earth = 1) - 0.815
Volume (Earth = 1) - 0.857
Average density - 5.25 g/cm3
The average temperature on the surface is about 470 oC
Axis deviation - 117° 3"
Orbital deviation relative to the ecliptic - 3°4"
Surface pressure (Earth = 1) - 90
Atmosphere - carbon dioxide (96.5%), nitrogen (3.5%), traces of oxygen and other elements.
Named after the goddess of love, the planet Venus has always attracted the attention of people. Looking into the sky, Venus can be easily seen in the morning and evening hours(it does not rise high above the earth's horizon), but it is the brightest among the stars, its magnitude is -4.4-4.8. Venus is the second closest planet to the Sun after Mercury and the closest planet to Earth. In many respects: diameter, mass, gravity and basic composition, Venus is very similar to our planet, only a little smaller. For some time it was believed that there was life there, just like on our planet, with seas and oceans, with land and forests. It is classified as an Earth-like planet. I would like to note that Venus has always been one of the most beloved planets of earthlings, which is why they endowed her with a beautiful female name, composed myths, poems and songs about her, comparing her with the most beautiful and mysterious images.
Basic information about Venus.
The radius of Venus is 6051.8 km.
Weight – 4.87 10²⁴kg.
Density – 5.25 g/cm³.
Gravity acceleration -8.87m/sec.
The second escape velocity is 10.46 km/sec. The orbit is circular, the eccentricity is only 0.0068, the smallest among the planets of the Solar System.
The distance from the planet to the Sun is 108.2 million km.
Distance to Earth: 40 - 259 million km.
The period of revolution around the Sun (sidereal period) is 224.7 days, with an average orbital speed of 35.03 km/sec.
Proper rotation is equal to 243 Earth days.
The synodic period is 583.92 days.
Deviation of the rotation axis to the perpendicular to the ecliptic plane -3.39 degrees
The planet rotates in a direction different from the Earth and other planets (except Uranus).
A revolution around its own axis takes 243.02 days.
The length of a solar day on the planet is 15.8 Earth days.
The angle of inclination of the equator to the orbit is 177.3 degrees.
Orbit of Venus.
The orbit of Venus is simple (almost circular), and at the same time, very unique in the solar system. It has the smallest eccentricity (as noted above, equal to 0.0068). But the most significant and mysterious feature is that it rotates around its axis in the opposite direction of its orbit around the Sun. This is a rare phenomenon in the characteristics of the planets of the solar system (except for Uranus), which has the same characteristic feature. It rotates around an axis from east to west. If you look from its North Pole, it rotates clockwise in its orbit, although all the other planets in our system rotate counterclockwise. Why this happens remains a mysterious mystery at the current stage of development of science. The divergence in the direction of the planet's movement around its own axis in orbit gives us the length of the day on Venus (116.8 times longer than on our Earth), and therefore the Sun rises and sets only twice a year there. A day (i.e. day and night) is equal to 58.4 Earth days. The planet orbits the Sun in 224.7 days (sidereal period) at a speed of 34.99 km/sec, with its own rotation around its axis for 243 days (Earth day). The planet has its own unusual calendar, where the year lasts less than a day. Due to the slight inclination of the orbital plane to the equatorial plane, there are practically no seasonal changes on Venus. Due to the fact that the orbit of Venus is between the orbits of Mercury and our planet, and closer to the Sun than we are, earthlings can observe a change in phases on Venus, just like the Moon. For the first time such a change in phases was recorded in 1610 by Galileo, after he invented the telescope, and while observing Venus. But in good cloudless weather, during the closest approach of Venus to the Earth, and without a telescope, you can see the crescent of Venus in the sky. You can observe the planet for a short time, only in the period after sunset and then before sunrise, since its orbit is no more than 48 degrees away from the Sun. In an inferior conjunction to the Earth, Venus always faces one side.
Atmosphere and climate.
Lomonosov first spoke about the atmosphere of Venus in 1761. He observed its passage across the solar disk and noticed a small halo around the planet when entering and leaving the solar disk. Subsequently, thanks to research, it was found that the planet has a very strong atmosphere, almost 92 times greater in mass than the Earth’s. This is the most powerful atmosphere among Earth-like planets. Sometimes it reaches 119 bar (in Diana Canyon). Due to the huge greenhouse effect and proximity to the Sun, the temperature at the bottom of the atmosphere is very high, and on the surface often reaches 470-530⁰C, and daily fluctuations due to the large greenhouse effect are insignificant. The entire surface of Venus is hidden behind thick dense clouds (presumably made of sulfuric acid!); there are never clear days on the surface of this planet. Thanks to modern research, it has been established that carbon dioxide predominates in the atmosphere (its content is 97%). It's caused by something that doesn't happen metabolic processes carbon, and there are no life processes that would process this gas into biomass. The atmosphere also contains nitrogen-4%, water vapor (about 0.05%), thousandths of oxygen, as well as SO2, H2S, CO, HF, HCL. Sun rays pass through the atmosphere only partially, and mainly in the form of reusable scattered radiation. Visibility is approximately the same as on a cloudy day on Earth.
The climate of Venus is characterized by almost no seasonal changes. The temperature is very high, higher than Mercury and reaches 500 degrees Celsius due to the greenhouse effect. The clouds are located at an altitude of 30-50 km and have several layers. When studying clouds with ultraviolet light, they found that clouds move in the equator region from the east, almost straight, to the west for a period of 4 days, and blow at the level of multilayer clouds strong winds at a speed of 100m/sec. and more. Scientists have come to the conclusion that it is above the planet. at upper limits clouds, one general hurricane is raging, although on the very surface of the planet the wind weakens to 1 m/sec. It is believed that it is possible acid rain. A large number of thunderstorms have been identified, almost twice as many as on Earth. Their origin has not yet been established. The planet's magnetic field is very weak, but due to its proximity to the Sun and the strong force of gravity, tidal influences are very significant. and there is a lot of tension in these places electric field(more than on Earth.)
The sky above your head on the planet yellow color with a greenish tint, since the atmosphere and carbon dioxide almost do not transmit rays of a different spectrum. 
Internal structure and surface of Venus.
To date, scientists consider the most reliable model internal structure Venus has the most common, classical model, consisting of three shells: a thin crust (about 14 - 16 km thick and a density of 2.7 g/cm³), a mantle of molten silicate and a solid iron core, where there is no movement of liquid masses, which leads to very small magnetic field. It is assumed that the mass of the core is 30% of the total mass of the planet. The planet's center of mass relative to its geometric center is significantly shifted, by approximately 430 km.
Thanks to spacecraft research, a map of the surface of Venus was compiled. The planet looks like a dry, completely waterless and very hot desert with unsteady ripples. 85% of the surface is plains. Elevations account for 10%. The largest elevations are the Ishtar plateau and the Aphrodite plateau, elevated 3-5 km above the average plain level. They are also called the land of Ishtar and Aphrodite or the continents. high mountain- Maxwell on the Ishtar plateau, reaching an altitude of 12 km. There are also many large depressions of regular circular shape with a diameter of 10 to 200 km. There are relatively few impact craters, there are about 1000 of them. Their interior area is filled with lava, and sometimes petals from fragments of crushed rock that flew up stick out. A network of small cracks in the crust is often visible around the craters. There are also volcanic craters, grooves and lines in the crust. and entire rivers of basalt lavas. All this speaks of past tectonic activity on the planet. It should be said that during this period of research by spacecraft, no volcanic or tectonic activity was recorded on the planet. When landing the spacecraft, the soil surface was recorded as smooth rocky fragments of basalt rock with an average size of up to 1 meter. Approximately, knowing the frequency of bombardment of planets by asteroids, comets and meteorites, one can determine the age of the planet. According to these data, Venus is 0.5 - 1 million. years. The rules for naming the surface relief of Venus were approved in 1985 by the Nineteenth Assembly of the International Astronomical Union. Small craters received female names: Katya, Olya, etc., large ones - named after famous women, hills and plateaus received the names of goddesses, furrows and lines were named after warrior women. True, as always, there are exceptions, such as Mount Maxwell, Alpha and Beta regions.
Unfortunately, the beautiful and brightest silvery-white planet remains mysterious and mysterious to us. The main discovery of science is that Venus is lifeless, deserted, there is no water on it, and the surface is very hot. 
