Venus is the second planet from the Sun and belongs to the earth group. And with the advent of the ability to plow the expanses of space, they were able to get even more interesting information.
Planet Overview
Venus is located at a distance of about 108 million km from the Sun, which is why it is one of the hottest planets in the system. Thanks to the dense atmosphere, it is difficult to observe its surface, and for this people are forced to send spacecraft that land on it.
Interesting fact: due to the fact that the surface of Venus is covered with sulfur clouds, its surface cannot be viewed through a telescope. To study the terrain, in the 20th century, people used radio waves, sending them toward the planet.
Even in the Middle Ages, people realized that a bright star in the sky is a planet that reflects the sun's rays. This made it possible to track her path through the sky. Venus is similar in size and structure to the Earth, but due to different distances to the stars, both have different conditions.
Orbit and radius
Compared to other planets in the solar system, Venus is not large. Its radius is approximately 6052 km, which can not be compared with the same parameter for gas giants.
The planet has an orbit, which is an almost perfect circle. During rotation around the star, the distance to it varies in the range from 107.5 to 108.9 million km. The year on Venus lasts 224.65 days - it is during this period that it makes a full revolution in orbit. Around its axis, it rotates very slowly: one day is 247 Earth. Thus, the planet returns to the same point in space relative to the Sun faster than does a full revolution around the axis.
Physical characteristics of the planet - size, mass and others
Venus became one of the first planets that people began to study. Because of this, humanity now has quite accurate values for many of the parameters and characteristics of the planet:
- weight is 4.89 * 10’24 kg;
- surface area is 460 million square kilometers;
- volume - 928 billion cubic km;
- acceleration of gravity 8.88 m / s2;
- the density of the composition is 5.2 g / s3;
- the average temperature on the planet is 463 degrees Celsius;
- surface pressure is 92 times higher than earth;
- the axis tilt is 177.36 degrees.
Most of Venus’s properties are preserved due to large accumulations of metals and rocks. They give the planet integrity and density of the structure. There is also a theory that the core of a celestial body is a hot metal, heated to a liquid state.
Age of Venus
Like most objects in the solar system, Venus began to form about 4.6 billion years ago. To determine the age, scientists used radiocarbon dating. This method checks the life of most space objects, including planets. And almost always the study gives the same number. This indicates that all objects in the system are approximately the same age.
When the Sun appeared, a large amount of cosmic dust revolved around it. Particles constantly collided with each other, straying into single objects. This process continued until planets with an exact orbit were formed. We can assume that Venus once appeared and materials located in the vicinity of the Sun.
Scientists also believe that several hundred million years ago the surface of the planet was not as hot as it is now, and water oceans could exist on it. This is evidenced by the features of the landscape with large ravines. In some places of Venus there are still active volcanoes. It is estimated that its current form was formed about 400 million years ago. It was then that the surface turned into endless stone territories. What was the planet in the first 4 billionyears of its existence - remains a mystery.
Atmosphere
Venus has the densest atmosphere among the planets of the solar system. On the lower layers there is always a large accumulation of white clouds. Because of this, people for a long time could not find out what its surface looks like.
Most of the atmosphere is carbon dioxide (96%). The rest is nitrogen (3%) and sulfur (1%). This composition determines the high surface temperature. Carbon dioxide causes a strong greenhouse effect, due to which the temperature at an altitude of up to 2-3 km exceeds 460 degrees Celsius.
Interesting fact: only at an altitude of 200 km the temperature in the atmosphere of Venus approaches the Earth's and is equal to 46 degrees Celsius.
The mass of the atmosphere is 93 times higher than the Earth, due to which the pressure on the surface is also 90 times higher and amounts to 92 bar. Often, powerful winds appear on Venus, which move in space at a speed of 85 km / s. They can fly around the planet in 5 days, and sometimes generate lightning.
The composition and surface of Venus
The surface is much denser than that of the Earth, and has no internal magnetic fields. There are many volcanoes on the planet, 170 of which are considered large and can still function.
About a billion years ago, almost the entire surface of Venus was covered with lava, which constantly erupted outside, there were regular earthquakes. But at one point, volcanoes greatly reduced their activity, and scientists are still looking for the cause of this event. Now eruptions can still occur on the surface of the planet, but in small quantities - this is indicated by a periodic change in the amount of sulfur dioxide.
A considerable part of the surface is made up of craters, the sizes of which from several kilometers can reach several hundreds.
Venus structure
It’s quite difficult for scientists to study the structure of the planet, because spacecraft quickly fail due to high temperatures. Using seismometers, they were able to obtain some data on the structure of Venus.
It is believed that the thickness of the surface is approximately 50 km, and the main substance in it is silicon. Next begins the mantle, which goes deep into about 3,000 km. It is still unknown what it consists of, since there is no way to do any analysis. In the center of Venus is a core of iron and nickel. Researchers are still wondering if it is liquid or solid.
Significantly in the study of the structure of the planet, the fact that it belongs to the earth group helps, since all its representatives have similar properties.
The core of Venus
The core of the planet is located at a depth of approximately 3,500 km. It’s quite difficult for scientists to research it, because any spacecraft that has landed on the surface quickly fails due to high temperatures. And if on Earth people calmly use seismometers, then there are big problems with this on the second planet from the Sun.
Since Venus is similar in structure to the Earth, it can be assumed that the same core is located inside it. However, scientists still cannot decide whether it is in a liquid or solid state. The planet does not have a magnetic field, but it appears during convection of the liquid core. However, it can still exist in Venus, simply because of the dense surface, it cannot break out and become noticeable to measuring instruments.
Also, the state of the core of Venus could change over time. It has already been established that something happened on the planet millions of years ago, because of which its structure has seriously changed. Perhaps the core was previously liquid, but gradually hardened.
Weather and Climate on Venus
It is believed that there used to be a climate on the planet that was very different from the current one. Because of this, Venus had a lot of water, and oxygen prevailed in the atmosphere. However, due to inexplicable reasons, the magnetosphere stopped working, which resets the protective layer of the planet.The solar wind began to corrode the atmosphere, sending hydrogen and water into outer space.
Interesting fact: many spacecraft sent to Venus break down at the stage of entry into the atmosphere. The record holder for work on the surface of the planet is a probe that has worked 127 minutes.
Now the average surface temperature is 460 degrees Celsius. On it regularly winds walk, accelerating to high speeds. In past centuries, astronomers believed that on Venus the climate is similar to Earth. They thought that a dense cloud of veils appeared due to water vapor, because there is a lot of water on the planet. But in the 60s, when spacecraft rushed into the sky, it became known that the cloud curtain has a sulfur base, moreover, acid rains regularly come from it, which evaporate, not reaching the surface.
Temperature on Venus
As mentioned above, the average temperature on Venus is equal to 460 degrees Celsius. Moreover, if on Earth this parameter varies in a wide range, then on the second planet from the Sun it is approximately the same value, regardless of the selected point.
Due to the small inclination of the axis, only 3 degrees, there is no change of seasons. Sulfur vapor and a high density of the atmosphere do not allow heat to go into open space, because of which it is distributed over the surface and maintains a high temperature.
Winds on Venus
Almost all the winds of Venus move from west to east. They drag behind them a dense layer of clouds, also causing them to move in space. Because of this, observing the following of the winds is not difficult.
Interesting fact: The maximum wind speed recorded on Venus is 700 km / h. Such a hurricane flies around the planet in less than half of the earth's day.
The average wind speed on the planet is 350 km / h. Moreover, the higher they are located in the atmosphere, the faster they move. If you go down directly to the surface, then on it the air currents will move no faster than 5-10 km / h.
Water on Venus
Since the temperature on Venus is several hundred degrees, it is easy to guess that in the liquid state water on its surface cannot exist in principle. Studies of the planet’s atmosphere proved that it still contains water vapor, but its share is only 0.002% of the total amount of substances.
This discovery hints that billions of years ago there could have been water on Venus, and the climate was colder. But due to regular collisions with meteorites and the disappearance of the magnetosphere, the climate became several times hotter. Because of this, all available seas and oceans quickly evaporated. And if heat is retained on the surface, then water vapor molecules could well leave the atmosphere and go into outer space. It is worth noting that if the magnetosphere also disappears on Earth someday, the planet’s climate will become much warmer, and almost the entire surface will turn into a desert.
Satellites
Venus has no moons. It is believed that in the early stages of life, the planet possessed such, but the Sun could absorb them, since it has a greater attractive force. Another reason for the disappearance of celestial bodies could be regular attacks of meteorites.
Despite the fact that Venus cannot boast of the presence of nearby bodies, she is not alone. The planet has one quasi-satellite - the asteroid VE68, discovered in the 2002th year. For already 7000 years, he has been accompanying the planet, following a similar orbit, but according to estimates, after five centuries, he will move enough distance from it to lose the status of a quasi-satellite.
Earth and Venus
Both planets have much in common, which is why they are often called sisters. Venus is only slightly inferior to the Earth in size: its diameter is 95% of the earth. Other parameters are also slightly lower than that of the third planet: gravity acceleration (90%), mass (81.5%), volume (85.7%), surface area (90%).The structure of celestial bodies also coincides: in the center is a metal core shrouded in mantle and bark.
But besides the similarities between Earth and Venus, there are many differences. The latter does not have convection of the nucleus, the magnetosphere does not function, which is why the surface temperature is much higher. The atmospheric pressure on the second planet is 93 times greater, which also affects the climate. An equally important difference is the complete absence of water, while there are plenty of fluids on Earth.
Clouds and the greenhouse effect on Venus
Clouds are located at a distance of 48 to 65 km. They are a dense shell of sulfuric acid and carbon dioxide, through which almost no sunlight. It is assumed that initially they were not above the planet, but unknown circumstances led to education.
Interesting fact: Venus illumination reaches only 3000 lux. For comparison, on a sunny day there can be 25,000 lux on the street.
Carbon dioxide and dense clouds do not allow heat to escape into the atmosphere, due to which the surface is very hot, a greenhouse effect appears. It helps maintain temperature.
What type of planet does Venus belong to?
Venus belongs to the earth group, which includes the planets of the first four. Also there are Mercury, Earth and Mars. The density of Venus is 5.204 g / m3, which is a fairly high indicator and is only 0.3 g / m3 inferior to the earth.
The affiliation of Venus to the earth group greatly simplified the process of its study. Due to the aggressive environment and high temperatures, the landing of space satellites on the surface is almost impossible. And since the terrestrial planets have similar properties, researchers in the 20th century were able to build many hypotheses regarding the composition, structure and characteristics, based on similar data obtained during the study of Earth and Mars. Decades later, they were confirmed in practice when people began to make devices that could work for some time on the surface of Venus.
Discovery story
Ancient people watched Venus with their naked eyes. Since at certain times the distance between the planet and the Earth is only several tens of millions of kilometers, it is clearly visible in the sky as a white spot. However, at that time there were no technologies that made it possible to make out a mysterious object in detail. And people observed in the sky in the morning and in the evening only a white spot, which was mistaken for two different stars.
In 1581 BC Babylonian astronomers have come to the conclusion that these stars are one object, moreover, it is a planet. Then her first description was made.
Interesting fact: despite the discovery of Babylonian astronomers, until the VI century BC it was believed that Venus is not a planet.
In 1032, the scientist Avicenn proved that Venus is closer to the sun than the Earth. To do this, he traced her path in orbit within sight. After about 600 years, Galileo established the phases of the planet and described them. In 1761, Mikhail Lomonosov, who discovered the atmosphere on it, made a contribution to understanding the structure of Venus. In the 20s of the last century, people first examined the celestial body using ultraviolet rays. By the 60s, astronomers already had a clear idea of the properties of the planet, which expanded due to the landing of spacecraft on its surface.
Who discovered Venus?
It is impossible to say exactly who owns the discovery of the planet. Even astronomers of antiquity observed the planet, but considered it a bright star due to the strong reflection of sunlight. When Copernicus drew up a model of the system, it became clear that this “luminary" moves in the sky like a planet, which means that it is.
In 1610, Galileo, using the telescope he invented. examined Venus and was the first to conclude that its surface is hidden from the eye by thick clouds.
Venus Research
With the development of space technology in the second half of the 20th century, people began to actively study the planets of the solar system. In the 60s, the USSR sent several spacecraft to Venus, which were supposed to study its features. However, not one of the satellites could achieve its goal.
At the same time, the Americans sent the Mariner-2 spacecraft. He approached the surface of the planet at a distance of 34.8 thousand km. From this distance, the satellite was able to measure the approximate surface temperature. Then scientists first established that Venus is the hottest planet in the solar system. This confirmed the absence of life.
In 1966, the Venus-3 apparatus managed to land on the surface, but immediately fell into disrepair. The next prototype, which arrived on the planet a year later, broke during landing, but managed to convey accurate data on temperature and pressure. Three years later, Venus-7 crashed during landing, but for 23 minutes transmitted information from the surface.
Since then, humanity has abandoned attempts to land on the planet. Now spacecraft are sent to Venus only for the purpose of observing at a safe distance. For example, the Magellan device from the 89th to the 93rd years was in orbit and studied the appearance of the planet by 98%.
Now scientists are still developing large-scale programs for sending probes to the second planet from the Sun, and they are helping to receive more and more information.
Why is Venus called that?
Even in ancient times, the Babylonians identified the planet with love and romantic feelings. Because of this, they called her Ishtar, in honor of the goddess of femininity. Later, Roman astronomers replaced her name with Venus, because that's what they called their goddess of love. Since then, such a name has been assigned to the second planet from the Sun. The ancient Greeks called her Aphrodite, in honor of her goddess of love.
The ancient Egyptians also watched the planet, but mistook it for two different stars that appear twice a day. Because of this, they called them Morning and Evening.
