Venus is the second planet farthest from the Sun (the second planet in the solar system).
Venus belongs to the terrestrial planets and is named after the ancient Roman goddess of love and beauty. Venus has no natural satellites. Has a dense atmosphere.
Venus has been known to people since ancient times.
Venus' neighbors are Mercury and Earth.
The structure of Venus is a subject of controversy. The most probable is: an iron core with a mass of 25% of the mass of the planet, a mantle (extends 3300 kilometers deep into the planet) and a crust 16 kilometers thick.
A significant part of the surface of Venus (90%) is covered with solidified basaltic lava. On it there are vast hills, the largest of which are comparable in size to the earth's continents, mountains and tens of thousands of volcanoes. Impact craters on Venus are practically absent.
Venus has no magnetic field.
Venus is the third brightest object in the Earth's sky after the Sun and Moon.
Orbit of Venus
The average distance from Venus to the Sun is just under 108 million kilometers (0.72 astronomical units).
Perihelion (nearest point in orbit to the Sun): 107.5 million kilometers (0.718 astronomical units).
Aphelion (farthest point of the orbit from the Sun): 108.9 million kilometers (0.728 astronomical units).
The average velocity of Venus in its orbit is 35 kilometers per second.
The planet makes one revolution around the Sun in 224.7 Earth days.
The length of a day on Venus is 243 Earth days.
The distance from Venus to Earth varies from 38 to 261 million kilometers.
The direction of rotation of Venus is opposite to the direction of rotation of all (except Uranus) planets of the solar system.
Venus is the second planet from the sun in the solar system, named after the Roman goddess of love. It is one of the brightest objects on celestial sphere, the "morning star" that appears in the sky at dawn and dusk. Venus is similar to Earth in many ways, but not at all as friendly as it seems from afar. The conditions on it are completely unsuitable for the emergence of life. The surface of the planet is hidden from us by an atmosphere of carbon dioxide and clouds of sulfuric acid, which create the strongest greenhouse effect. The opacity of the clouds does not allow us to study Venus in detail, therefore it still remains one of the most mysterious planets for us.
a brief description of
Venus revolves around the Sun at a distance of 108 million km, and this value is almost constant, since the planet's orbit is almost perfectly circular. At the same time, the distance to the Earth changes significantly - from 38 to 261 million km. The radius of Venus is on average 6052 km, the density is 5.24 g / cm³ (dense than the earth). The mass is equal to 82% of the mass of the Earth - 5 10 24 kg. Acceleration free fall also close to the earth - 8.87 m / s². Venus has no satellites, but until the 18th century, repeated attempts were made to search for them, which were unsuccessful.
The planet makes a full circle in orbit in 225 days, and the day on Venus is the longest in the entire solar system: they last as much as 243 days, longer than the Venusian year. Venus moves in orbit at a speed of 35 km/s. The inclination of the orbit to the plane of the ecliptic is quite significant - 3.4 degrees. The axis of rotation is almost perpendicular to the plane of the orbit, due to which the northern and southern hemispheres are illuminated by the Sun almost equally, and there is no change of seasons on the planet. Another feature of Venus is that the directions of its rotation and circulation do not coincide, unlike other planets. It is assumed that this is due to a powerful collision with a large celestial body that changed the orientation of the axis of rotation.
Venus is classified as a terrestrial planet, and is also called the sister of the Earth because of the similarity in size, mass and composition. But the conditions on Venus can hardly be called similar to those on Earth. Its atmosphere, composed mainly of carbon dioxide, is the densest of all planets of the same type. Atmospheric pressure is 92 times greater than the earth's. Thick clouds of sulfuric acid envelop the surface. For visible radiation, they are opaque, even with artificial satellites, which for a long time made it difficult to see what was under them. Only radar methods for the first time made it possible to study the relief of the planet, since the Venusian clouds turned out to be transparent to radio waves. It was found that there are many traces of volcanic activity on the surface of Venus, but no active volcanoes were found. There are very few craters, which speaks of the "youth" of the planet: its age is about 500 million years.
Education
Venus is very different from other planets in the solar system in terms of its conditions and features of movement. And it is still impossible to answer the question, what is the reason for such uniqueness. First of all, whether it is the result of natural evolution or geochemical processes due to proximity to the Sun.
According to a single hypothesis of the origin of the planets in our system, they all arose from a giant protoplanetary nebula. Due to this, the composition of all atmospheres was the same for a long time. After some time, only the cold giant planets were able to retain the most common elements - hydrogen and helium. From the planets closer to the Sun, these substances were actually "blown away" into outer space, and heavier elements - metals, oxides and sulfides - entered their composition. The atmospheres of the planets were formed primarily due to volcanic activity, and their initial composition depended on the composition of volcanic gases in the depths.
Atmosphere
Venus has a very powerful atmosphere that hides its surface from direct observation. Most of it consists of carbon dioxide (96%), 3% is nitrogen, and even less other substances - argon, water vapor and others. In addition, clouds of sulfuric acid are present in a large volume in the atmosphere, and it is they that make it opaque to visible light, but infrared, microwave and radio radiation pass through them. The atmosphere of Venus is 90 times more massive than the Earth's, and also much hotter - its temperature is 740 K. The reason for this heating (more than on the surface of Mercury, which is closer to the Sun) lies in the greenhouse effect that occurs due to the high density of carbon dioxide - the main component atmosphere. The height of the Venusian atmosphere is about 250-350 km.
The atmosphere of Venus constantly and very rapidly circulates and rotates. Its rotation period is many times less than that of the planet itself - only 4 days. The wind speed is also huge - about 100 m / s in upper layers which is much more than on Earth. However, at low altitudes, the movement of winds is significantly weakened and reaches only about 1 m/s. Powerful anticyclones are formed at the poles of the planet - polar vortices having an S-shape.
Like the earth, the Venusian atmosphere consists of several layers. The lower layer - the troposphere - is the densest (99% of total mass atmosphere) and extends to an average height of 65 km. Due to the high surface temperature, the lower part of this layer is the hottest in the atmosphere. The wind speed here is also low, but with increasing altitude it increases, while the temperature and pressure decrease, and at an altitude of about 50 km they are already approaching the earth's values. It is in the troposphere that the greatest circulation of clouds and winds is observed, and weather phenomena are observed - whirlwinds, hurricanes rushing at great speed, and even lightning that strikes here twice as often as on Earth.
Between the troposphere and the next layer - the mesosphere - there is a thin boundary - the tropopause. Here the conditions are most similar to those on earth's surface: The temperature is between 20 and 37 °C and the pressure is about the same as at sea level.
The mesosphere occupies heights from 65 to 120 km. Its lower part has an almost constant temperature of 230 K. At an altitude of about 73 km, a cloud layer begins, and here the temperature of the mesosphere gradually decreases with a height of up to 165 K. At about an altitude of 95 km, the mesopause begins, and here the atmosphere again begins to heat up to values of the order of 300 400 K. The temperature is the same for the overlying thermosphere, which extends to the upper boundaries of the atmosphere. It should be noted that, depending on the illumination of the surface of the planet by the Sun, the temperatures of the layers on the day and night sides differ significantly: for example, daytime values for the thermosphere are about 300 K, and nighttime values are only about 100 K. In addition, Venus also has an extended ionosphere at altitudes 100 - 300 km.
At an altitude of 100 km in the atmosphere of Venus there is an ozone layer. The mechanism of its formation is similar to that of the earth.
There is no own magnetic field on Venus, but there is an induced magnetosphere formed by streams of ionized particles of the solar wind, bringing with them the magnetic field of the star, frozen into the coronal matter. The lines of force of the induced magnetic field, as it were, flow around the planet. But due to the absence of its own field, the solar wind freely penetrates into its atmosphere, provoking its outflow through the magnetospheric tail.
The dense and opaque atmosphere practically does not allow sunlight to reach the surface of Venus, so its illumination is very low.
Structure
Photo from an interplanetary spacecraft
Information about the relief and internal structure of Venus has become available relatively recently thanks to the development of radar. Surveys of the planet in the radio range made it possible to create a map of its surface. It is known that more than 80% of the surface is filled with basaltic lava, and this suggests that the modern relief of Venus is formed mainly by volcanic eruptions. Indeed, there are a lot of volcanoes on the surface of the planet, especially small ones, with a diameter of about 20 kilometers and a height of 1.5 km. Are there active ones among them? this moment impossible to say. There are much fewer craters on Venus than on other terrestrial planets, since the dense atmosphere prevents most of them from penetrating through it. celestial bodies. In addition, spacecraft have discovered hills up to 11 km high on the surface of Venus, occupying about 10% of the entire area.
single model internal structure Venus has not been developed to this day. According to the most probable of them, the planet consists of a thin crust (about 15 km), a mantle more than 3000 km thick and a massive iron-nickel core in the center. The absence of a magnetic field on Venus can be explained by the absence of moving charged particles in the core. This means that the core of the planet is solid, since there is no movement of matter in it.
Observation
Since of all the planets Venus comes closest to the Earth and is therefore the most visible in the sky, it will not be difficult to observe it. It is visible to the naked eye even in the daytime, but at night or at dusk, Venus appears before the eyes as the brightest "star" in the celestial sphere with a magnitude of -4.4 m. Thanks to such an impressive brightness, the planet can be observed through a telescope even during the day.
Like Mercury, Venus does not move far from the Sun. The maximum angle of its deviation is 47 °. It is most convenient to observe it shortly before sunrise or immediately after sunset, when the Sun is still below the horizon and does not interfere with observation with its bright light, and the sky is still not dark enough for the planet to shine too brightly. Since the details on the disk of Venus are barely perceptible during observations, it is necessary to use a high-quality telescope. And even in it, most likely, only a grayish circle without any details. However, under good conditions and high-quality equipment, sometimes you can still see dark bizarre shapes and white spots formed by atmospheric clouds. Binoculars are useful only for finding Venus in the sky and its simplest observations.
The atmosphere on Venus was discovered by M.V. Lomonosov during its passage across the solar disk in 1761.
Venus, like the Moon and Mercury, has phases. This is due to the fact that its orbit is closer to the Sun than the Earth's, and therefore, when the planet is between the Earth and the Sun, only part of its disk is visible.
The tropopause zone in the atmosphere of Venus, due to conditions similar to those on Earth, is being considered for placement of research stations there and even for colonization.
Venus has no satellites, but for a long time there was a hypothesis according to which it was previously Mercury, but due to some external catastrophic impact, it left its gravitational field and became an independent planet. In addition, Venus has a quasi-satellite - an asteroid whose orbit of rotation around the Sun is such that it does not get out of the influence of the planet for a long time.
In June 2012, the last transit of Venus across the solar disk in this century took place, fully observed in pacific ocean and almost throughout Russia. The last passage was observed in 2004, and earlier ones in the 19th century.
Because of the many similarities to our planet, life on Venus was considered possible for a long time. But since it became known about the composition of its atmosphere, the greenhouse effect and other climatic conditions, it is obvious that such terrestrial life on this planet is impossible.
Venus is one of the candidates for terraforming - changing the climate, temperature and other conditions on the planet in order to make it habitable for terrestrial organisms. First of all, for this it will be necessary to deliver enough water to Venus to start the process of photosynthesis. It is also necessary to make the temperature on the surface significantly lower. To do this, it is necessary to negate the greenhouse effect by converting carbon dioxide into oxygen, which could be handled by cyanobacteria, which would need to be sprayed into the atmosphere.
Venus- the second inner planet of the solar system, having a period of revolution of 224.7 Earth days. The planet got its name in honor of the goddess of love Venus from the Roman pantheon.
The planet Venus is often referred to as Earth's "cosmic sister". Indeed, according to its external data, this planet resembles the Earth. Its diameter is only 600 km less than the earth's, and the force of gravity on the surface of Venus is almost the same as on Earth. A weight of 1 kg, being transferred to Venus, would weigh 850 g there.
However, this is where the similarities end - for earthlings, landing on a "sister" planet would be fatal: pressure 90 times higher than Earth's and a temperature of +400 degrees Celsius are only some of the "surprises" that Venus has prepared for us.
The average distance of Venus from the Earth is 41 million km at the nearest point (2 times closer than ) and 259 million km at the far point of the orbit. The distance from Venus to the Sun is 108.2 million km.
Venus has an almost spherical shape, the planet's orbit is almost circular, its eccentricity is 0.0068 - the smallest in the solar system. The speed of movement of Venus in orbit is 35 km / s. The orbital period is 224.7 Earth days, and the rotation period around the axis is 243.02 Earth days.
A feature of rotation around its axis is that Venus rotates in the opposite direction, compared to other planets in the solar system. Such a movement is called retrograde.
Due to this, one day on Venus lasts 116.8 Earth days (i.e. half of the Venusian year). Thus, day and night on Venus last for 58.3 Earth days.
The surface of the planet is constantly covered with dense clouds.
The planet Venus as it can be seen from orbit - the surface of the planet is never visible due to a veil of clouds
The atmosphere of the planet Venus
The cloudy veil on Venus is completely opaque, and if we found ourselves on the surface of this planet, we would be forever deprived of the view of the Sun and the starry sky. Therefore, when viewing Venus through telescopes, we do not see the surface of the planet, but only observe the upper edge of the cloudiness.
As for the chemical composition of the Venusian atmosphere, its only reliably determined component is carbon dioxide, the relative content of which, according to astronomical data, should be about 95%. There is also reliable evidence of the presence of water vapor in the gaseous envelope of Venus. In the upper atmosphere of Venus, the oxygen content does not exceed 0.1% of its content in the same layers of the Earth's atmosphere.
The greenhouse effect also occurs in the atmospheres of other planets. But if in the atmosphere of Mars it raises the average temperature near the surface by 9°, in the atmosphere of the Earth by 35°, then in the atmosphere of Venus this effect reaches 400 degrees. The recorded maximum temperature on the surface is +480°C - above the melting point of lead!
Such a high temperature requires an explanation. Calculations show that it cannot be the result of Venus' proximity to the Sun alone. There must be some additional factors that contribute to warming up. Most likely, such a factor is the extremely strong "greenhouse effect" of the Venusian atmosphere. It is likely that the gaseous envelope of the planet, while transmitting visible sunlight well, almost completely absorbs infrared radiation resulting from the heating of the planet's surface.
On Earth, the greenhouse effect is associated with the presence of carbon dioxide and water vapor in the atmosphere. On Venus, carbon dioxide is also present in large quantities. But carbon dioxide in the infrared region of the spectrum absorbs far from all wavelengths. Water vapor could "fill in" these "windows of transparency". But only very small amounts of water have been found in the atmosphere of Venus. Of course, the possibility is not ruled out that some other gas absorbs the planet's thermal radiation, but which one is completely unclear. In addition, it is noteworthy that the day and night sides of the planet are equally hot.
In this regard, a natural assumption arises about the high internal temperature of a cloudy planet. It is possible that Venus is currently undergoing violent volcanic activity. In this case, the high temperatures found on the surface of Venus are explained by a powerful influx of energy from its depths.
Space exploration of Venus
The space probe "Venera-1" was the first spacecraft from Earth built specifically to study other planets, it was launched on February 12, 1961, but communication with it was soon lost.
Therefore, the first artificial apparatus to "measure" Venus on its own was the American Mariner 2, launched on August 27, 1962 and already in December of the same year transmitted valuable information about the enormous surface temperature and the complete absence of a magnetic field around the planet.
But then the Soviet "Venus" made up for the first failures - 16 Soviet spacecraft transmitted to Earth a colossal amount of information about planet No. 2, and "Venera-7" on December 15, 1970 made a soft landing on Venus and successfully transmitted not only data on atmospheric parameters, but also photographs of the surface - the first photographs of the surface of another planet that earthlings saw. In total, Venera-7 worked for 23 minutes, until the harsh conditions of the “evil sister” of the earth put an end to the mission of the apparatus.
Venera-13 and Venera-14 found that the soil of Venus consists of 50% silica, 16% aluminum alum, and 11% magnesium oxide.
The period of rotation of the planet and the coordinates of its North Pole, obtained as a result of joint processing of onboard radar and Doppler measurements of Magellan and Venera-15, Venera-16 for 20 reference points on the surface of Venus, turned out to be as follows: Rotation period T = 243.0183 Earth days. Right Ascension = 272.57. Declination = 67.14.
And the third brightest object in the sky after the Sun and the Moon. Sometimes this planet is called sister of the earth, which is associated with a certain similarity in mass and size. The surface of Venus is covered with a completely impenetrable layer of clouds, the main component of which is sulfuric acid.
naming Venus the planet received in honor of the Roman goddess of love and beauty. Even in the time of the ancient Romans, people already knew that this Venus is one of four planets that differ from the Earth. It was the planet's highest brightness, the visibility of Venus, that played a role in the fact that it was named after the goddess of love, and this allowed for years to associate the planet with love, femininity and romance.
For a long time it was believed that Venus and Earth are twin planets. The reason for this was their similarity in size, density, mass and volume. However, later scientists found that despite the obvious similarity of these planetary characteristics, the planets are very different from each other. We are talking about such parameters as the atmosphere, rotation, surface temperature and the presence of satellites (Venus does not have them).
As in the case of Mercury, human knowledge of Venus increased significantly in the second half of the twentieth century. Before the US and Soviet Union began to organize their missions since the 1960s, scientists still had hope that the conditions under the incredibly dense clouds of Venus could be habitable. But the data collected as a result of these missions proved the opposite - the conditions on Venus are too harsh for the existence of living organisms on its surface.
A significant contribution to the study of both the atmosphere and the surface of Venus was made by the USSR mission of the same name. The first spacecraft sent to the planet and flying past the planet was Venera-1, developed by the Energia Rocket and Space Corporation named after S.P. Koroleva (today NPO Energia). Despite the fact that communication with this ship, as well as with several other vehicles of the mission, was lost, there were those who were able not only to study the chemical composition of the atmosphere, but even reach the surface itself.
The first ship, launched on June 12, 1967, which was able to conduct atmospheric research was Venera-4. The spacecraft's descent module was literally crushed by pressure in the planet's atmosphere, but the orbital module managed to make a number of valuable observations and obtain the first data on Venus's temperature, density and chemical composition. The mission made it possible to determine that the planet's atmosphere consists of 90% carbon dioxide with a small amount of oxygen and water vapor.
The instruments of the orbiter indicated that Venus has no radiation belts, and the magnetic field is 3000 times weaker than the Earth's magnetic field. An indicator of solar ultraviolet radiation aboard the ship made it possible to reveal the hydrogen corona of Venus, the hydrogen content in which was about 1000 times less than in the upper layers of the Earth's atmosphere. The data were further confirmed by the Venera-5 and Venera-6 missions.
Thanks to these and subsequent studies, today scientists can distinguish two wide layers in the atmosphere of Venus. The first and main layer is clouds that cover the entire planet with an impenetrable sphere. The second is everything below these clouds. The clouds surrounding Venus extend from 50 to 80 kilometers above the planet's surface and are composed primarily of sulfur dioxide (SO2) and sulfuric acid (H2SO4). These clouds are so dense that they reflect 60% of all the sunlight that Venus receives back into space.
The second layer, which is below the clouds, has two main functions: density and composition. The combined effect of these two functions on the planet is enormous - it makes Venus the hottest and least hospitable of all the planets in the solar system. Due to the greenhouse effect, the temperature of the layer can reach 480 ° C., which allows heating the surface of Venus to the maximum temperatures in our system.
Clouds of Venus
Based on observations by the Venus Express satellite, which is overseen by the European Space Agency (ESA), scientists have for the first time been able to show how the weather conditions in the thick layers of clouds of Venus are related to the topography of its surface. It turned out that the clouds of Venus can not only interfere with the observation of the surface of the planet, but also give clues about what exactly is located on it.
It is believed that Venus is very hot due to the incredible greenhouse effect, which heats its surface to temperatures of 450 degrees Celsius. The climate on the surface is depressing, and it itself is very dimly lit, as it is covered by an incredibly thick layer of clouds. At the same time, the wind that is present on the planet has a speed not exceeding the speed of an easy run - 1 meter per second.
However, when viewed from afar, the planet, which is also called Earth's sister, looks very different - the planet is surrounded by smooth, bright clouds. These clouds form a thick layer twenty kilometers above the surface and thus much colder than the surface itself. The typical temperature of this layer is about -70 degrees Celsius, which is comparable to the temperatures found on Earth's cloud tops. In the upper layer of the cloud, weather conditions are much more extreme, with winds hundreds of times faster than on the surface and even faster than Venus' rotational speed.
With the help of Venus Express observations, scientists have been able to significantly improve the climate map of Venus. They were able to single out three aspects of the planet's cloudy weather at once: how fast the winds on Venus are able to circulate, how much water is contained in the clouds, and how bright these clouds are distributed across the spectrum (in ultraviolet light).
“Our results have shown that all of these aspects: wind, water content and cloud composition are somehow related to the properties of the surface of Venus,” said Jean-Loup Berteau of the LATMOS observatory in France, lead author of the new Venus Express study. "We used spacecraft observations that cover a period of six years, from 2006 to 2012, and this allowed us to study patterns of long-term weather changes on the planet."
Surface of Venus
Before the radar studies of the planet, the most valuable data on the surface were obtained using the same Soviet space program "Venus". The first vehicle to make a soft landing on the surface of Venus was the Venera 7 space probe, launched on August 17, 1970.
Despite the fact that even before landing, many of the ship's instruments had already failed, he was able to detect pressure and temperature indicators on the surface, which amounted to 90 ± 15 atmospheres and 475 ± 20 ° C.
1 - descent vehicle;
2 - solar panels;
3 – celestial orientation sensor;
4 - protective panel;
5 - corrective propulsion system;
6 - manifolds of the pneumatic system with control nozzles;
7 – cosmic particle counter;
8 - orbital compartment;
9 - radiator-cooler;
10 - low-directional antenna;
11 - highly directional antenna;
12 - pneumatic system automation unit;
13 - cylinder of compressed nitrogen
The subsequent Venera-8 mission turned out to be even more successful - it was possible to obtain the first samples of the surface soil. Thanks to the gamma spectrometer installed on the ship, it was possible to determine the content of radioactive elements in the rocks, such as potassium, uranium, and thorium. It turned out that the soil of Venus resembles terrestrial rocks in its composition.
The first black-and-white photographs of the surface were taken by the Venera-9 and Venera-10 probes, which were launched almost one after the other and made a soft landing on the planet's surface on October 22 and 25, 1975, respectively.
After that, the first radar data of the Venusian surface were obtained. The pictures were taken in 1978, when the first of the American spacecraft Pioneer Venus arrived in orbit around the planet. The maps created from the images showed that the surface consisted mainly of plains, which were formed by powerful lava flows, as well as two mountainous regions, called Ishtar Terra and Aphrodite. The data were subsequently confirmed by the Venera 15 and Venera 16 missions, which mapped the northern hemisphere of the planet.
The first color images of the surface of Venus and even a sound recording were obtained using the Venera-13 descent module. The module's camera took 14 color and 8 black and white photographs of the surface. Also, for the first time, an X-ray fluorescence spectrometer was used to analyze soil samples, thanks to which it was possible to identify the priority rock at the landing site - leucite alkaline basalt. The average surface temperature during module operation was 466.85 °C and the pressure was 95.6 bar.
The module of the Venera-14 spacecraft launched after it was able to transmit the first panoramic images of the planet's surface:
Despite the fact that obtained with space program"Venus" photographic images of the planet's surface are still the only and unique, represent the most valuable scientific material, these photographs could not give a large-scale idea of the planet's relief. After analyzing the results obtained, the space powers focused on the radar research of Venus.
In 1990, he began his work in the orbit of Venus spacecraft called Magellan. He managed to take better radar images, which turned out to be much more detailed and informative. So, for example, it turned out that out of 1000 impact craters that Magellan discovered, none of them exceeded two kilometers in diameter. This led scientists to believe that any meteorite less than two kilometers in diameter simply burned up when passing through the dense Venusian atmosphere.
Because of the thick clouds that surround Venus, the details of its surface cannot be seen using simple photographic means. Fortunately, scientists were able to use the radar method to obtain the necessary information.
Although both photographic tools and radar work by collecting radiation that is reflected from an object, they have a big difference and that lies in reflecting forms of radiation. Photo captures visible light radiation, while radar mapping reflects microwave radiation. The advantage of using radar in the case of Venus proved to be clear, as microwave radiation can pass through the planet's thick clouds, while the light needed for photography is unable to do so.
Thus, additional studies of the size of the craters have helped shed light on factors that speak to the age of the planet's surface. It turned out that small impact craters are practically absent on the surface of the planet, but there are no large-diameter craters either. This led scientists to believe that the surface was formed after a period of heavy bombardment, between 3.8 and 4.5 billion years ago, when a large number of impact craters formed on the inner planets. This indicates that the surface of Venus has a relatively young geological age.
The study of the planet's volcanic activity revealed even more character traits surfaces.
The first feature is the huge plains described above, created by lava flows in the past. These plains cover about 80% of the entire Venusian surface. Second characteristic feature are volcanic formations that are very numerous and varied. In addition to the shield volcanoes that exist on Earth (for example, Mauna Loa), many flat volcanoes have been discovered on Venus. These volcanoes are different from Earth volcanoes in that they have a distinctive flat disc-shaped shape due to the fact that all the lava contained in the volcano erupted at once. After such an eruption, the lava comes out in a single stream, spreading in a circular fashion.
Geology of Venus
As with other terrestrial planets, Venus is essentially made up of three layers: crust, mantle, and core. However, there is something that is very intriguing - the bowels of Venus (unlike or) are very similar to the bowels of the Earth. Due to the fact that it is not yet possible to compare the true composition of the two planets, such conclusions were made based on their characteristics. At the moment, it is believed that the crust of Venus has a thickness of 50 kilometers, the thickness of the mantle is 3,000 kilometers, and the core has a diameter of 6,000 kilometers.
In addition, scientists still do not have an answer to the question of whether the core of the planet is liquid or is solid. All that remains is, in view of the similarity of the two planets, to assume that it is as liquid as that of the Earth.
However, some studies indicate that the core of Venus is solid. To prove this theory, the researchers cite the fact that the planet lacks a magnetic field. Simply put, planetary magnetic fields are the result of the transfer of heat from inside the planet to its surface, and the liquid core is a necessary component of this transfer. The insufficient strength of the magnetic fields, according to this concept, indicates that the existence of a liquid core in Venus is simply impossible.
Orbit and rotation of Venus
The most notable aspect of Venus's orbit is its uniformity in distance from the Sun. The eccentricity of the orbit is only .00678, that is, the orbit of Venus is the most circular of all the planets. Moreover, such a small eccentricity indicates that the difference between the perihelion of Venus (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 on 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 rotation of the planet around its axis is counterclockwise when viewed from the "upper" plane of the orbit, but in fact, the rotation of Venus is retrograde or clockwise. The reason for this is currently unknown, but there are two popular theories to explain this phenomenon. The first one points to the 3:2 spin-orbit resonance of Venus with the Earth. Proponents of the theory believe that over billions of years, the force of gravity of the Earth changed the rotation of Venus to its current state.
Proponents of another concept doubt that the Earth's gravitational force was strong enough to change the rotation of Venus in such a fundamental way. Instead, they refer to the early period of the solar system, when the formation of the planets took place. According to this view, the original rotation of Venus was similar to the rotation of other planets, but was changed to the current orientation when the young planet collided with a large planetesimal. The impact was so powerful that it turned the planet upside down.
The second unexpected discovery related to the rotation of Venus is its speed.
In order to make a full rotation around its axis, the planet takes about 243 Earth days, that is, a day on Venus is longer than on any other planet and a day on Venus is comparable to a year on Earth. But even more scientists were struck by the fact that a year on Venus is almost 19 Earth days less than one day of Venus. Again, no other planet in the solar system has such properties. Scientists associate this feature just with the reverse rotation of the planet, the features of the study of which were described above.
- Venus is the third brightest natural object in the Earth's sky after the Moon and the Sun. The planet has a visual magnitude of -3.8 to -4.6, making it visible even on a clear day.
Venus is sometimes called the "morning star" and "evening star". This is due to the fact that representatives of ancient civilizations took this planet for two different stars, depending on the time of day.
One day on Venus is longer than one year. Due to the slow rotation around its axis, a day lasts 243 Earth days. A revolution in the orbit of the planet takes 225 Earth days.
Venus is named after the Roman goddess of love and beauty. It is believed that the ancient Romans named her so because of the high brightness of the planet, which in turn could come from the time of Babylon, whose inhabitants called Venus "the bright queen of the sky."
Venus has no moons or rings.
Billions of years ago, Venus' climate could have been similar to Earth's. Scientists believe that Venus once had a lot of water and oceans, but due to high temperatures and the greenhouse effect, the water has boiled away, and the surface of the planet is currently too hot and hostile to support life.
Venus rotates in the opposite direction to the other planets. Most of the other planets rotate counterclockwise around their axis, but Venus, like Venus, rotates clockwise. This is known as retrograde rotation and may have been caused by a collision with an asteroid or other space object, which changed the direction of its rotation.
Venus is the hottest planet in the solar system with an average surface temperature of 462°C. Also, Venus has no axial tilt, which means there are no seasons on the planet. The atmosphere is very dense and contains 96.5% carbon dioxide, which traps heat and causes the greenhouse effect that vaporized water sources billions of years ago.
The temperature on Venus practically does not change with the change of day and night. This is due to the too slow movement of the solar wind over the entire surface of the planet.
The age of the Venusian surface is about 300-400 million years. (The Earth's surface is about 100 million years old).
The atmospheric pressure of Venus is 92 times stronger than on Earth. This means that any small asteroids entering Venus' atmosphere will be crushed by the enormous pressure. This explains the lack of small craters on the surface of the planet. This pressure is equivalent to the pressure at a depth of about 1000 km. in the oceans of the earth.
Venus has a very weak magnetic field. This surprised scientists, who had expected Venus to have a magnetic field similar in strength to Earth's. One of possible causes this is that Venus has a solid inner core or that it does not cool.
Venus is the only planet in the solar system named after a woman.
Venus is the closest planet to Earth. The distance from our planet to Venus is 41 million kilometers.
Photo of Venus
The first and only to date photographic images of the surface of Venus were obtained by spacecraft of the Soviet space program "Venus". But there are also pictures of the planet taken by the Akatsuki probe.
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Venus- the second planet of the solar system: mass, size, distance from the Sun and planets, orbit, composition, temperature, Interesting Facts, research history.
Venus is the second planet from the Sun and the hottest planet in the solar system. For ancient people, Venus was a constant companion. It is an evening star and the brightest neighbor, which has been observed for thousands of years after the recognition of planetary nature. That is why it appears in mythology and was noted in many cultures and peoples. With each century, interest has grown, and these observations have helped to understand the structure of our system. Before proceeding with the description and characterization, find out interesting facts about Venus.
Interesting facts about the planet Venus
A day lasts longer than a year
- The rotation axis (sidereal day) takes 243 days, and the orbital path covers 225 days. A sunny day lasts 117 days.
Rotates in the opposite direction
- Venus is retrograde, which means it rotates in the opposite direction. Perhaps in the past there was a collision with large asteroid. It also lacks satellites.
Second brightest in the sky
- For an earthly observer, only the Moon is brighter than Venus. With a magnitude of -3.8 to -4.6, the planet is so bright that it occasionally shows up in the middle of the day.
Atmospheric pressure is 92 times that of the earth
- Although they are similar in size, the surface of Venus is not as cratered as the thick atmosphere obliterates incoming asteroids. The pressure on its surface is comparable to what is felt at great depths.
Venus is an earthly sister
- The difference in their diameters is 638 km, and the mass of Venus reaches 81.5% of the Earth's. Also converge in structure.
Called the Morning and Evening Star
- Ancient people believed that they had two different objects in front of them: Lucifer and Vesper (among the Romans). The fact is that its orbit overtakes the earth's and the planet appears at night or during the day. It was described in detail by the Maya in 650 BC.
hottest planet
- The temperature indicator of the planet rises to 462 ° C. Venus is not endowed with a remarkable axial tilt, therefore it is devoid of seasonality. The dense atmospheric layer is represented by carbon dioxide(96.5%) and retains heat, creating a greenhouse effect.
The study ended in 2015
- In 2006, the Venus Express apparatus was sent to the planet, which entered its orbit. Initially, the mission covered 500 days, but then it was extended until 2015. He managed to find more than a thousand volcanoes and volcanic centers with a length of 20 km.
The first mission belonged to the USSR
- In 1961, the Soviet probe Venera-1 set off for Venus, but contact was quickly cut off. The same thing happened to the American Mariner 1. In 1966, the USSR managed to lower the first apparatus (Venus-3). This helped to see the surface hidden behind a dense acid haze. It was possible to advance in research with the advent of radiographic mapping in the 1960s. It is believed that in the past the planet had oceans that evaporated due to rising temperatures.
Size, mass and orbit of the planet Venus
There are many similarities between Venus and the Earth, so the neighbor is often called the sister of the Earth. By mass - 4.8866 x 10 24 kg (81.5% of the earth), surface area - 4.60 x 10 8 km 2 (90%), and volume - 9.28 x 10 11 km 3 (86.6%).
The distance from the Sun to Venus reaches 0.72 AU. e. (108,000,000 km), and the world is practically devoid of eccentricity. Its aphelion reaches 108,939,000 km, and its perihelion reaches 107,477,000 km. So we can assume that this is the most circular orbital path among all the planets. The bottom photo successfully demonstrated a comparison of the sizes of Venus and the Earth.
When Venus is located between us and the Sun, it comes closest to the Earth of all planets - 41 million km. This happens once every 584 days. It spends 224.65 days on the orbital path (61.5% of the Earth).
| Equatorial | 6051.5 km |
|---|---|
| Medium radius | 6051.8 km |
| Surface area | 4.60 10 8 km² |
| Volume | 9.38 10 11 km³ |
| Weight | 4.86 10 24 kg |
| Average density | 5.24 g/cm³ |
| Acceleration free fall at the equator |
8.87 m/s² 0.904g |
| first cosmic speed | 7.328 km/s |
| Second space velocity | 10.363 km/s |
| equatorial speed rotation |
6.52 km/h |
| Rotation period | 243.02 days |
| Axis Tilt | 177.36° |
| right ascension north pole |
18 h 11 min 2 s 272.76° |
| North declination | 67.16° |
| Albedo | 0,65 |
| Apparent stellar magnitude |
−4,7 |
| Angular diameter | 9.7"–66.0" |
Venus is not quite a standard planet and stands out to many. If almost all the planets in order in the solar system rotate counterclockwise, then Venus does it clockwise. In addition, the process is slow and one of its days covers 243 earth. It turns out that the sidereal day is longer than the planetary year.
The composition and surface of the planet Venus
They believe that internal structure resembles the earth with a core, mantle and crust. The core must be at least partially in a liquid state, because both planets cooled almost simultaneously.
But plate tectonics speaks volumes. The crust of Venus is too strong, which led to a decrease in heat loss. Perhaps this was the reason for the absence of an internal magnetic field. Study the structure of Venus in the figure.
The creation of the surface was influenced by volcanic activity. There are approximately 167 large volcanoes on the planet (more than on Earth), whose height exceeds 100 km. Their presence is based on the absence of tectonic movement, which is why we are looking at the ancient crust. Its age is estimated at 300-600 million years.
It is believed that volcanoes can still spew lava. Soviet missions, as well as ESA observations, confirmed the presence of lightning storms in the atmospheric layer. There is no usual precipitation on Venus, so lightning can be created by a volcano.
Also, a periodic increase / decrease in the amount of sulfur dioxide was noted, which speaks in favor of eruptions. The IR view captures the appearance of hot spots hinting at lava. It can be seen that the surface ideally preserves craters, of which there are approximately 1000. They can reach 3-280 km in diameter.
You will not find smaller craters, because small asteroids simply burn up in dense atmosphere. To reach the surface, it is necessary to exceed 50 meters in diameter.
Atmosphere and temperature of the planet Venus
Viewing the surface of Venus was previously extremely difficult, because the view was blocked by an incredibly dense atmospheric haze, represented by carbon dioxide with small impurities of nitrogen. The pressure is 92 bar, and the atmospheric mass exceeds the earth's by 93 times.
Let's not forget that Venus is the hottest among solar planets. The average is 462°C, which is consistently held night and day. It's all about the presence of a huge amount of CO 2 , which forms a powerful greenhouse effect with clouds of sulfur dioxide.
The surface is isothermal (does not affect the distribution or changes in temperature at all). The minimum axis tilt is 3°, which also prevents the appearance of seasons. Changes in temperature are observed only with height.
It is worth noting that the temperature at the highest point of Mount Maxwell reaches 380 ° C, and atmospheric pressure - 45 bar.
If you find yourself on the planet, you will immediately encounter powerful wind currents, whose acceleration reaches 85 km / s. They go around the entire planet in 4-5 days. In addition, dense clouds can form lightning.
Atmosphere of Venus
Astronomer Dmitry Titov about the temperature regime on the planet, clouds of sulfuric acid and the greenhouse effect:
History of the study of the planet Venus
People in ancient times knew about its existence, but mistakenly believed that there were two different objects in front of them: morning and evening stars. It is worth noting that they officially began to perceive Venus as a single object in the 6th century BC. e., but as early as 1581 BC. e. there was a Babylonian tablet, which clearly explained the true nature of the planet.
For many, Venus has become the personification of the goddess of love. The Greeks named after Aphrodite, and for the Romans, the morning appearance became Lucifer.
In 1032, Avicenna first observed the passage of Venus in front of the Sun and realized that the planet is located towards the Earth. closer to the sun. In the 12th century, Ibn Bajai found two black spots, which were later explained by the transits of Venus and Mercury.
In 1639 Jeremiah Horrocks oversaw the transit. Galileo Galilei at the beginning of the 17th century used his instrument and noted the phases of the planet. This was an extremely important observation, which indicated that Venus went around the Sun, which means that Copernicus was right.
In 1761, Mikhail Lomonosov discovered the atmosphere on the planet, and in 1790 it was noted by Johann Schroeter.
The first serious observation was made by Chester Lyman in 1866. Around the dark side of the planet, a full ring of light was noted, which once again hinted at the presence of an atmosphere. The first UV survey was carried out in the 1920s.
Spectroscopic observations told about the features of rotation. Vesto Slifer tried to determine the Doppler shift. But when he failed, he began to suspect that the planet was rotating too slowly. Moreover, in the 1950s realized that we are dealing with retrograde rotation.
Radar was used in the 1960s. and received rotations close to modern indicators. Details like Mount Maxwell could be talked about thanks to the Arecibo Observatory.
Exploration of the planet Venus
For the study of Venus, scientists of the USSR actively began, who in the 1960s. sent several spaceships. The first mission ended unsuccessfully, as it did not even reach the planet.
The same thing happened with the American first attempt. But Mariner 2, sent in 1962, managed to pass at a distance of 34,833 km from the planetary surface. Observations confirmed the presence of high heat, which immediately ended all hopes for the existence of life.
The first apparatus on the surface was the Soviet Venera-3, which landed in 1966. But the information was never obtained, because the connection was immediately interrupted. In 1967, Venera-4 rushed. As it descended, the mechanism determined the temperature and pressure. But the batteries quickly ran out and communication was lost while he was still in the process of descending.
Mariner 10 flew at an altitude of 4000 km in 1967. He received information about the pressure, atmospheric density and composition of the planet.
In 1969, Venera 5 and 6 also arrived, which managed to transmit data in 50 minutes of descent. But Soviet scientists did not give up. Venera-7 crashed on the surface, but managed to transmit information for 23 minutes.
From 1972-1975 The USSR launched three more probes, which managed to get the first pictures of the surface.
Mariner 10 took more than 4,000 images on its way to Mercury. At the end of the 70s. NASA prepared two probes (Pioneers), one of which was to study the atmosphere and create a surface map, and the second 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 the 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. He spent 4.5 years in orbit and displayed 98% of the surface and 95% of the gravitational field. In the end, he was sent to his death in the atmosphere to get density data.
Galileo and Cassini watched Venus fleetingly. 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.
The Japanese agency JAXA sent the Akatsuki probe in 2010, but it failed to reach orbit.
In 2013, NASA sent an experimental suborbital space telescope that studied UV light from the planet's atmosphere to accurately investigate Venus' watery history.
Also in 2018, ESA may launch the BepiColombo project. There are also rumors about the Venus In-Situ Explorer project, which could start in 2022. Its purpose is to study the characteristics of regolith. Russia can also send the Venera-D spacecraft in 2024, which they plan to lower to the surface.
Due to the proximity to us, as well as the similarity in certain parameters, there were those who expected to discover life on Venus. Now we know about her hellish hospitality. But there is an opinion that once it had water and a favorable atmosphere. Moreover, the planet is inside the habitable zone and has an ozone layer. Of course, the greenhouse effect led to the disappearance of water billions of years ago.
However, this does not mean that we cannot count on human colonies. The most suitable conditions are located at an altitude of 50 km. These will be air cities based on durable airships. Of course, all this is difficult to do, but these projects prove that we are still interested in this neighbor. In the meantime, we are forced to observe it at a distance and dream about future settlements. Now you know which planet Venus is. Be sure to follow the links to learn more interesting facts and view the surface map of Venus.
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