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 finding life like ours in accessible space.
For a long time, the solar system, shrouded in legends no less than in fog, was among the candidates for settlement by organic life.
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. Carbon dioxide and nitrogen were detected in the process. Their share in the air envelope is distributed as 96 and 3%, respectively.
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 gives the 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, the formation of the greenhouse effect became possible precisely due to the evaporation of large amounts of water. The steam allows sunlight to pass through, but traps heat at the surface, thereby causing the temperature to rise.
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. The photographs and images taken helped to create a fairly detailed relief map.
High temperatures have thinned the planet's crust, so there are a large number of 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 for this: a dense atmosphere, which plays the role of a kind of screen, and active processes that erase 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 that reach 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 of its internal shells 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 that bear a female name, and, like a beautiful girl, it attracts glances and 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.
On the distant star Venus
The sun is fiery and golden,
On Venus, ah, on Venus
The trees have blue leaves.
Nikolay Gumilyov
The planet of the Roman goddess of love and beauty, the morning and evening star... You've probably seen it - early in the morning, when the sun is about to rise, it is the last to disappear in the brightening sky. Or, on the contrary, it is the first to light up against the background of a fading sunset - the brightest, not counting the Sun and Moon, 17 times brighter than the brightest star - Sirius. If you look closely, it doesn’t even look like a star - it doesn’t twinkle, but shines with an even white light.
But at midnight you will never see her. For an earthly observer, Venus does not move away from the Sun more than 48°, because we are looking at its orbit “from the outside.” Therefore, Venus is clearly visible in two cases: when it is to the right, west of the Sun - this is called western elongation - at this time it sets before the Sun and rises before the Sun, so it is clearly visible before sunrise; and when it is to the left of the Sun and follows it across the sky during the day, then it is visible in the evening (Fig. 1). The period when the planet is close to the Earth-Sun line is called connection(the planet “connects” with the Sun), at this time it is not visible.
However, this is not entirely true. Venus is not visible to the eye when it is close to the Sun, but through a telescope - if you know exactly where to look for it - you can see it. (By the way, the task is to draw what Venus looks like through a telescope, for example, in eastern elongation.) And occasionally it happens that for an earthly observer it passes not near the Sun, but directly across its disk. During such a passage, observing it through a telescope, Lomonosov discovered the atmosphere of Venus. Whenever O Most of Venus was already on the disk of the Sun; for a moment he saw a thin luminous rim around the rest of the planet (Fig. 2). Many people saw this headband, but did not attach any importance to it. And only Lomonosov realized that it was the oblique rays of the sun that illuminated the atmosphere of the planet, like a flashlight in the dark illuminates smoke and makes it visible.
This atmosphere was not a gift at all. To begin with, it turned out that it is opaque to “ordinary” (visible) light and does not allow one to see the surface of the planet: it’s like trying to see the bottom of a pan through a layer of milk. But people learned the main thing only when they tried to land a descent module on Venus.
Venus is almost the same size as the Earth, and not much smaller in mass; it would seem that these two planets are almost the same. So, even at the beginning of the twentieth century, one could assume that trees grow on Venus and that anyone lives at all. Or that, for example, earthlings could settle on it. However, these hopes were not justified: the first device that tried to land on Venus (in 1967) was crushed before it even reached the surface!
It turned out that Venus has monstrous atmospheric pressure: almost 100 times more than on Earth. On every square centimeter of the surface, a column of air presses with such force as if a hundred-kilogram weight were placed on this centimeter on Earth! The density of Venusian “air” is only 14 times less than the density of water. The temperature is always - both during the day and at night - equal to 470°C, more than in the hottest place on Mercury! In addition, the atmosphere, which consists mainly of carbon dioxide (CO 2), contains a bunch of poisonous and caustic sulfur compounds, including sulfuric acid. Until now, not a single descent vehicle - and there were about a dozen of them - has lasted in this environment for more than two hours...
Try to imagine this picture. The sky on Venus is orange, always covered with clouds of sulfuric acid. The sun is never visible behind a continuous layer of clouds. Naturally, there is no water - at this temperature it has evaporated long ago (and before, it seems, there were oceans!). Sometimes acid rain falls (literally: instead of water there is acid), but it does not reach the surface - it evaporates from the heat. There is almost no wind below, only 1 m/s, but the “air” is so dense that even such a weak wind raises dust and small stones, all of this seems to be floating in the air. But above, at the height of the clouds, a giant hurricane is constantly raging - the wind speed there reaches 100 m/s, that is, 360 km/h, and even more! (Where this hurricane came from is still unknown.)
How did this happen? Why is this picture so different from the one on earth? Let's figure it out.
Sulfur compounds and carbon dioxide (of which 96% on Venus) entered the atmosphere from volcanoes. There are many volcanoes - thousands, the entire surface is covered with frozen lava. Perhaps some of the volcanoes are still active, but so far it has not been possible to see eruptions on Venus.
All of these “volcanic” gases have heavy molecules: for example, a carbon dioxide molecule weighs 1.5 times more than the nitrogen and oxygen molecules that make up the earth’s atmosphere. And there are a lot of them. That’s why the “air” there is so dense and heavy.
Why is the temperature so high? Again, volcanic gases are to blame, primarily carbon dioxide. He creates the so-called Greenhouse effect, the essence of which is this. The sun illuminates the planet (Earth, for example) and thereby heats it, transferring some energy to it every second (through rays of light). Thanks to this energy, winds blow, rivers flow, plants and animals live. But energy never disappears, it can only transform from one type to another. We ate a sandwich - the (chemical) energy hidden in it was spent on heating our body. A river flows - the water hits the stones and also heats them up. So, ultimately, the energy transferred by the Sun to the planet turns into heat - the planet warms up. Where does the energy go next? The heated surface of the planet emits slightly different radiation, invisible to the eye - infrared. The hotter the surface, the stronger the radiation. This radiation goes into space and carries away “extra” energy - exactly as much as it comes from the Sun. A balance is maintained: as much as you take, return as much.
What if you return (that is, emit) less than you took (received from the Sun)? Energy will begin to accumulate on the planet, and the temperature of the surface and air will rise. A more heated surface emits more infrared rays - and soon equilibrium will be restored, but at a higher temperature.
The greenhouse effect is overheating, which arises precisely from such a temporary imbalance. The fact is that carbon dioxide absorbs infrared rays. The surface of the planet emits them, but the carbon dioxide in the atmosphere does not release them out into space! Solar energy with visible light gets in, but the atmosphere doesn’t let it out. This is how energy accumulates until the entire atmosphere warms up so much that its upper layer can finally radiate the required amount of energy into space and restore balance. This is what happened on Venus - in order to restore balance, its surface had to heat up by 400 degrees. This can happen to the Earth if too much carbon dioxide and other “complex” gases accumulate in its atmosphere!
There is another interesting feature. Almost everything in the solar system - all the planets and b O Most of the asteroids revolve around the Sun in the same direction. And around their axis, all the large planets rotate in the same direction - all except one. Venus rotates “unlike everyone else,” however, very slowly: 1 revolution around its axis in 243 Earth days, while the Venusian year lasts 225 Earth days. That is, Venus rotates around the Sun even a little faster than around its axis! Having trained on Mercury, you will, of course, easily figure out how long the day would be and how long the night would be on Venus if these two periods coincided (this answer is almost real, since the difference is small). The resonance with the Sun is again incomplete - and again, perhaps the reason is in the Earth: just as Mercury in its “waltz” always turns to us with the same side when meeting, so Venus in each conjunction with the Sun is turned to the Earth in the same way. So there is an inaccurate resonance with the Sun, but there is a resonance with the Earth.
Why is she spinning in the wrong direction? Unclear. There are different hypotheses, each more doubtful than the other. All of them, one way or another, boil down to the fact that “in childhood” some kind of misfortune happened to Venus. Someone pushed or hit... But the answer to the previous question is well-known - why do all the other planets spin so amicably (and all except Mercury quickly) in the same direction? Try to guess.
Answers
1. When looking through a telescope, Venus's disk is clearly visible, so its phases are also visible - like those of the Moon. And for the same reason: only its illuminated side is visible. In eastern elongation we see exactly half a circle “in the shape of the letter P” (see Fig. 1 of the article), like the Moon in the first quarter. But unlike the Moon, the month of Venus does not grow at this time, but decreases: then the Earth and the Sun will be on opposite sides of it, and its crescent will become very narrow.
2. If the year and sidereal day coincided, day and night would last a quarter of a year - see the figure below. In fact, a solar day on Venus lasts 116 Earth days, that is, more than half a year, but less than half a sidereal day.
3. Rotation (both annual and daily) in one direction is a consequence of a common origin. All the planets were “stick together” from lumps (planetesimals) in a large protoplanetary cloud, which as a whole slowly rotated in one (random) direction, like soup in a pan if you stir it slightly with a spoon. When the Sun was formed, the entire cloud became denser (shrinked towards the center) and, like a figure skater who pressed his hands to his body in a “screw”, began to rotate faster; in physics this is called conservation of angular momentum. Individual lumps also compressed (and very strongly), forming planets, and their rotation around their axis greatly accelerated. Therefore, the planets rotate around their axis quickly; Mercury slowed down only later.
Artist Maria Useinova
On Earth, such pressure can also be found - in the ocean, at a depth of 1 km.
In fact, there is a small greenhouse effect (not due to carbon dioxide, but due to water vapor) on Earth, and it is very useful: without it, the temperature would be 20–30 degrees lower than it is now.
Formally, Uranus is also spinning “in the wrong direction,” but we’ll talk about it separately.
You just need to draw a picture... If that doesn't work, see the answers.
The planet closest to Earth and 2nd from the Sun. However, before the start of space flights, very little was known about Venus: the entire surface of the planet was hidden by dense clouds that did not allow it to be explored. These clouds are composed of sulfuric acid, which intensely reflect light.
Therefore, it is not possible to see the surface of Venus in visible light. The atmosphere of Venus is 100 times denser than Earth's and consists of carbon dioxide.
Venus is illuminated by the Sun no more than the Earth is illuminated by the Moon on a cloudless night.
However, the Sun heats the planet's atmosphere so much that it is constantly very hot - the temperature rises to 500 degrees. The culprit of such strong heating is the greenhouse effect, which forms the atmosphere from carbon dioxide.
History of discovery
Through a telescope, even a small one, you can easily notice and track the shift in the visible phase of the disk of the planet Venus. They were first observed in 1610 by Galileo. The atmosphere was discovered by M.V. Lomonosov on June 6, 1761, when the planet passed across the disk of the Sun. This cosmic event was pre-calculated and eagerly awaited by astronomers around the world. But only Lomonosov focused his attention on the fact that when Venus came into contact with the disk of the Sun, a “hair-thin glow” appeared around the planet. Lomonosov gave a correct scientific explanation of this phenomenon: he considered it a consequence of the refraction of solar rays in the atmosphere of Venus.
“Venus,” he wrote, “is surrounded by a light atmosphere, such (if only not more) than that which surrounds our globe.”
Characteristics
- Distance from the Sun: 108,200,000 km
- Length of day: 117d 0h 0m
- Mass: 4.867E24 kg (0.815 Earth mass)
- Gravity acceleration: 8.87 m/s²
- Circulation period: 225 days
Pressure on the planet Venus reaches 92 earth atmospheres. This means that for every square centimeter a column of gas weighing 92 kilograms presses.
Diameter of Venus only 600 kilometers less than on Earth and is 12104 km, and the gravity is almost the same as on our planet. A kilogram weight on Venus will weigh 850 grams. Thus, Venus is very close to Earth in size, gravity and composition, which is why it is called an “Earth-like” planet, or “sister Earth”.
Venus rotates around its axis in the direction opposite to the direction of other planets in the solar system - from east to west. Only one other planet in our system behaves this way - Uranus. One rotation around its axis is 243 Earth days. But a Venusian year takes only 224.7 Earth days. It turns out that a day on Venus lasts more than a year! On Venus there is a change of day and night, but there is no change of seasons.
Research
Nowadays, the surface of Venus is explored both with the help of spacecraft and with the help of radio emission. Thus, it was noticed that a considerable part of the surface is occupied by hilly plains. The soil and sky above it are orange in color. The surface of the planet is pitted with an abundance of craters formed from the impacts of large meteorites. The diameter of these craters reaches 270 km! It is also common knowledge that Venus has tens of thousands of volcanoes. New research has revealed that some of them are valid.
The third brightest object in our sky. Venus is called the Morning Star, and also the Evening Star, because from Earth it looks brightest shortly before sunrise and sunset (in ancient times it was believed that morning and evening Venus were different stars). Venus shines brighter in the morning and evening sky than the brightest stars.
Venus is lonely and has no natural satellites. This is the only planet in the solar system that received its name in honor of a female deity - the rest of the planets are named after male gods.
The planet Venus is our closest neighbor. Venus comes closer to Earth than any other planet, at a distance of 40 million km or closer. The distance from the Sun to Venus is 108,000,000 km, or 0.723 AU.
Venus's dimensions and mass are close to those of Earth: the diameter of the planet is only 5% less than the diameter of the Earth, its mass is 0.815 that of the Earth, and its gravity is 0.91 that of the Earth. At the same time, Venus rotates very slowly around its axis in the direction opposite to the rotation of the Earth (i.e., from east to west).
Despite the fact that in the XVII-XVIII centuries. Various astronomers have repeatedly reported the discovery of natural satellites of Venus. It is currently known that the planet does not have any.
Atmosphere of Venus
Unlike other terrestrial planets, studying Venus using telescopes turned out to be impossible, since M. V. Lomonosov (1711 - 1765), observing the passage of the planet against the background of the Sun on June 6, 1761, he established that Venus is surrounded by “a noble air atmosphere, such (if only not greater) than that which surrounds our globe.”
The planet's atmosphere extends to a height 5500 km, and its density is 35 times the density of the earth. Atmospheric pressure in 100 times higher than on Earth, and reaches 10 million Pa. The structure of the atmosphere of this planet is shown in Fig. 1.
The last time astronomers, scientists and amateurs were able to observe the passage of Venus against the background of the solar disk in Russia was on June 8, 2004. And on June 6, 2012 (i.e., with an 8-year interval), this amazing phenomenon can be observed again. The next passage will take place only after 100 years.
Rice. 1. The structure of the atmosphere of Venus
In 1967, the Soviet interplanetary probe Venera 4 for the first time transmitted information about the planet’s atmosphere, which consists of 96% carbon dioxide (Fig. 2).
Rice. 2. Composition of the atmosphere of Venus
Due to the high concentration of carbon dioxide, which, like a film, retains heat at the surface, the planet experiences a typical greenhouse effect (Fig. 3). Thanks to the greenhouse effect, any existence of liquid water near the surface of Venus is excluded. The air temperature on Venus is approximately +500 °C. Under such conditions, organic life is excluded.
Rice. 3. Greenhouse effect on Venus
On October 22, 1975, the Soviet probe Venera 9 landed on Venus and transmitted a television report from this planet to Earth for the first time.
General characteristics of the planet Venus
Thanks to Soviet and American interplanetary stations, it is now known that Venus is a planet with complex terrain.
Mountainous terrain with a height difference of 2-3 km, a volcano with a base diameter of 300-400 km, and you
the hundredth is about 1 km, a huge basin (length 1500 km from north to south and 1000 km from west to east) and relatively flat areas. In the equatorial region of the planet there are more than 10 ring structures, similar to the craters of Mercury, with a diameter of 35 to 150 km, but highly smoothed and flat. In addition, in the planet’s crust there is a fault 1500 km long, 150 km wide and about 2 km deep.
In 1981, the stations “Venera-13” and “Venera-14” examined samples of the planet’s soil and transmitted the first color photographs of Venus to the ground. Thanks to this, we know that the surface rocks of the planet are similar in composition to terrestrial sedimentary rocks, and the sky above the horizon of Venus is orange-yellow-green.
At present, human flights to Venus are unlikely, but at an altitude of 50 km from the planet, the temperature and pressure are close to conditions on Earth, so it is possible to create interplanetary stations here to study Venus and to recharge spacecraft.
At the center of the solar system is our daytime star, the Sun. There are 9 large planets orbiting around it together with their satellites:
- Mercury
- Venus
- Earth
- Jupiter
- Saturn
- Neptune
- Pluto
The age of the Solar System was determined by scientists based on laboratory isotopic analysis of terrestrial rocks, as well as meteors and lunar soil samples delivered to Earth by spacecraft. It turned out that the oldest of them are about 4.5 billion years old. Therefore, it is believed that all the planets were formed at approximately the same time - 4.5 - 5 billion years ago.
Venus, the second closest planet to the Sun, is almost the same size as Earth, and its mass is more than 80% of Earth's mass. Located closer to the Sun than our planet, Venus receives more than two times more light and heat from it than Earth. However, from the shadow side on Venus The prevailing frost is more than 20 degrees below zero, since the sun's rays do not reach here for a very long time. She has very dense, deep and very cloudy atmosphere, preventing us from seeing the surface of the planet. The atmosphere is a gaseous shell, on Venus, discovered by M.V. Lomonosov in 1761, which also showed the similarity of Venus with the Earth.
The average distance from Venus to the Sun is 108.2 million km; it is practically constant, since Venus's orbit is closer to a circle than that of any other planet. At times, Venus approaches Earth at a distance of less than 40 million km.
The ancient Greeks gave this planet the name of their best goddess Aphrodite, but the Romans then changed it in their own way and called the planet Venus, which, in general, is the same thing. However, this did not happen immediately. At one time it was believed that there were two planets in the sky at once. Or rather, back then there were still stars, one dazzlingly bright, visible in the morning, another, the same one, in the evening. They were even called differently, until the Chaldean astronomers, after long observations and even longer reflections, came to the conclusion that the star was still one, which does them credit as great specialists.
The light of Venus is so bright that if there is neither the Sun nor the Moon in the sky, it causes objects to cast shadows. However, when viewed through a telescope, Venus is disappointing, and it is not surprising that until recent years it was considered the “planet of secrets.”
In 1930 some information has appeared about Venus. It was found that its atmosphere consists mainly of carbon dioxide, which can act as a kind of blanket, trapping the sun's heat. Two pictures of the planet were popular. One pictured the surface of Venus as almost entirely covered in water, in which primitive life forms could develop, as was the case on Earth billions of years ago. Another imagined Venus as a hot, dry and dusty desert.
The era of automatic space probes began in 1962, when the American Mariner 2 probe passed near Venus and transmitted information that confirmed that its surface was very hot. It was also found that the period of rotation of Venus around its axis is long, about 243 Earth days, longer than the period of revolution around the Sun (224.7 days), therefore, on Venus, “days” are longer than a year and the calendar is completely unusual.
It is now known that Venus rotates in the opposite direction - from east to west, and not from west to east, like the Earth and most other planets. For an observer on the surface of Venus, the Sun rises in the west and sets in the east, although in reality the cloudy atmosphere completely obscures the sky.
Following Mariner 2, a soft landing on the surface of Venus was carried out by several Soviet automatic vehicles parachuted through the dense atmosphere. At the same time, a maximum temperature of about 5300C was recorded, and the pressure at the surface was almost 100 times greater than the atmospheric pressure at sea level on Earth.
Mariner 10 approached Venus in February 1974 and transmitted the first images of the upper layer of clouds. This device passed near Venus only once - its main target was the innermost planet - Mercury. However, the images were of high quality and showed the striped structure of the clouds. They also confirmed that the rotation period of the cloud top layer is only 4 days, so the structure of the atmosphere of Venus is not similar to that of Earth.
Meanwhile, American radar studies have shown that there are large but small craters on the surface of Venus. The origins of the craters are unknown, but since such a dense atmosphere would be subject to severe erosion, they are unlikely to be very old by "geological" standards. The cause of the craters may be volcanism, so the hypothesis that volcanic processes are occurring on Venus cannot yet be ruled out. Several mountainous areas have also been found on Venus. The largest mountainous region, Ishtar, is twice the size of Tibet. In its center a giant volcanic cone rises to a height of 11 km. The clouds were found to contain large amounts of sulfuric acid (possibly even fluorosulfuric acid).
The next important step was taken in October 1975, when two Soviet devices - “Venera - 9” and “Venera - 10″ - made a controlled landing on the surface of the planet and transmitted images to Earth. The images were retransmitted by the orbital compartments of the stations, which remained in near-planetary orbit at an altitude of about 1500 km. This was a triumph for Soviet scientists, even despite the fact that both “Venera - 9” and “Venera - 10” transmitted for only no more than an hour, until they ceased to operate once and for all due to too high temperatures and pressure.
It turned out that the surface of Venus was strewn with smooth rocky fragments, similar in composition to terrestrial basalts, many of which were about 1 m in diameter.
The surface was well lit: according to the description of Soviet scientists, there was as much light as there is in Moscow on a cloudy summer afternoon, so that searchlights from the devices were not even required. It also turned out that the atmosphere did not have excessively high refractive properties, as expected, and all the details of the landscape were clear. The temperature on the surface of Venus was 4850 degrees Celsius, and the pressure was 90 times higher than the pressure at the surface of the Earth. It was also discovered that the cloud layer ends at an altitude of about 30 km. Below is an area of hot, acrid fog. At altitudes of 50 - 70 km there are powerful cloud layers and hurricane winds blow. The atmosphere on the surface of Venus is very dense (only 10 times less than the density of water).
Venus is not the hospitable world it was once supposed to be. With its atmosphere of carbon dioxide, clouds of sulfuric acid and terrible heat, it is completely unsuitable for humans. Under the weight of this information, some hopes collapsed: after all, less than 20 years ago, many scientists considered Venus a more promising object for space exploration than Mars.
Venus has always attracted the views of writers - science fiction writers, poets, scientists. Much has been written about her and about her and, probably, much more will be written, and it is even possible that someday some of her secrets will be revealed to people.