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Venus in the solar system
Venus is the second planet in the solar system, the average distance between it and the Sun isputs 108.2 million kilometers. Its orbit is placed inside the orbit of the Earth, so Venus, as and Mercury, is an inner planet.
The orbit of Venus is closer in shape to a circle thanorbits of other planets. Venus makes a revolutionthe circle of the Sun in 224.7 Earth days, moving at a speed of 35 kilometers per second. During inferior conjunctions, Venus may approach Earth less than 40 million km - closer than any other majorshoy planets of the solar system. Synodic pe-rhod (from one lower connection to another) veins 583.92 days, and five such periods almost exactly fit into eight Earth years. The best conditions for the visibility of Venus fall on the period elongation, when the angular distance of Venus from the Sun nza reaches 48 degrees; for an earthly observer at a greater distance from our daytime star, it never moves away, so the planet is visible only after sunset ("evening star") or shortly before sunrise ("morning star"). Ancient astronomers at one time even assumed that these were two different celestial bodies, and gave them various names - Phosphorus and Lucifer.
Unusually proper rotation of Venus: long-the frequency of one revolution around the axis relative to the stars (sidereal day) exceeds the Venusian year and is equal toat 243.16 Earth days, and the direction of rotation is opposite to the rotation of most planets. Venus rotates around its axis in the opposite direction. board - from east to west (or clockwise -ke, when viewed from the side North Pole peace), and not from west to east, like the Earth and other planets, except for Uranus. The axis of rotation of Venus is almost perpendicular tocular to the orbital plane (the inclination of the equator to the plane of the orbit is about 2.6 °, or 177.4 °, taking into accountvolume of reverse rotation), so there is no change of seasons on the planet. One day there is like another,is the same duration and, apparently,bridges, the same weather. Due to the unusual combination directions and periods of rotation and circulation around the Sun, the change of day and night on Ve- nere occurs in almost 117 days, so day and night go on there for 58.5 days. The day that is usually compared with the year is the solar day, the synodic period of rotation. The synodic period is: 1/(1/243 + 1/224.7) = 116.7 Earth days-current (the plus sign is taken taking into account the opposite direction of rotation). This is how long a solar day lasts on Venus.
The uniformity of the weather intensifies strong greenhouse effect, creatingpervaded by the Venusian atmosphere.
Venus is similar to our Earth in size and mass. The radius of Venus is 6052 km (near the Earth - 6378 km). The mass of Venus is 0.815 of the mass of the Earth, the average density of the planet is 5240 kg / m 3,acceleration free fall on equa- tore 8.76 m / s (89% of the earth). Due to the slow rotation, the effect of the planet's roughness from the poles is absent.
After the Sun and Moon, Venus isbeing the brightest luminary of the earth's sky: its magnitude at the maximum sometimes exceeds -4.5 m, the planet is often observed in the daytime sky unarmed with a woman’s eye, and under favorable conditions, one can even observe the shadow from objects created by the light of Ve- ners (however, in the conditions of modern it is rather difficult for civilizations to find such conditions).
First look at Venus through the telescope
Hardly tried to study the planet not immediately after the invention of human your telescope. AT 1610 year Galileo Galileo was the first to observe the phase change inVenus, i.e. change in its visible shapewe are from a disk to a narrow sickle. "Not windows-what has been read and hidden has been read by me" - such which anagram was published by the great Galileo to reserve the rightthe championship of the opening of the change of phases in Venice ry. The anagram contained the message: "The mother of love imitates the figures of Qing- tii". This can be deciphered as follows: "the mother of love (Venus) is observed in various phases like the Moon (Qing- ii)". Was it not this discovery that the correctness of the heliocentric system was asserted? are we Copernicus?
Following the discovery of the Venusian phases, claims of other scientists for "discoveries" appeared, which, however, were not confirmed by anything. For example, Francesco Fontana from Naples in 1643 saw on Venus "mountains that lifted- for several tens of kilometers." The dispute about the "Himalayas" on Venus subsequently tvii did not die out, and the most curious thing is that modern planetologists have indeed discovered high mountain ranges there. The thing is that the terminator, the border of day and night, on Venus appears to be a broken line. Francesco Fontana believed that the unevenness of the terminator depends on the shadows cast by the relief. He naively applied to Venus the conclusions that at one time Gali-ley made in relation to the lunar terminator, where the brokenness of the action closely related to the lunar relief. Hence the absurd result, since the Venus terminator line depends only on the unevenness of its cloud cover. Beginning with XVII centuries, astronomers have repeatedly tried to "see" Venus, but no one has been able to find any detailed details on the surface of the planet. Because of dense clouds it represents- is homogeneous.
AT In 1761, Mikhailo Lomonosov observed the passage of the planet across the solar disk. As a result of these observations, the discovery of the atmosphere of Venus was made, described in the article "The phenomenon of Venus on the Sun, observed in the St. Petersburg Imperial Academy of Sciences on May 26, 1761". Watching the entry Venus on the disk of the Sun, Lomonosov noted the clouding of the edge of the solar disk at the first contact: "... Waiting for the entry of Venus into the Sun ... I finally saw that the solar edge of the anticipated entry became unclear and somewhat blurred, and before that it was very clean and equal everywhere ... "Cog Yes, the disk of Venus is almost completely drank on the disk of the Sun, around the part of the disk of the planet, which was still in the background of the sky, a thin rim of light flashed, close in brightness to the brightness Sun. Lomonosov called this bezel"thin as a hair radiance." Exactly the same light rim was observed by Lomonosov when Venus exited from the solar disk: "a pimple appeared on the edge of the Sun, which is all the more distinct committed, the closer Venus is to the performance laziness came."
The appearance of this rim was subsequently called the "Lomonosov phenomenon". The scientist gave him the correct explanation nie, writing: "This is nothing else looks like the refraction of the rays of the sun in the Venusian atmosphere, "and explained this idea with a drawing that showed the course of the refracted rays. On the basis of this, the following conclusion was made:" According to these notes, Mr. Advisor Lomonosov argues that the planet Venus is surrounded by a noble airy atmosphere, such (if only not more) that it pours around our globe of the earth.
This was, in fact, the second great discovery in the exploration of Venus. After him, it became clear thatxnost of Venus in the optical rangenever seen because ithidden from view by an impenetrable veil clouds.
atmosphere and surface
Despite the fact that Venus was studiedtelescopic methods almost 400years, only in the middle XX century, from the beginning scrap of the "space age of humanity", the picture of the chemical composition of the planet and the structure of its surface began to clear up.
Former hypotheses and conjectures of scientistsabout the boundless giant ocean that covered the entire surface of the planet, or about a waterless desert with unceasing dust storms were not elevated to the rank scientific theory. By- the surface of Venus is completely hidden powerful cloud cover, and only with the help of radars it is possible to "see" its relief.
Venus is the second planet farthest from the Sun (the second planet in the solar system).
Venus belongs to the planets terrestrial group 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.
The second planet from the Sun, Venus, is the closest to the Earth and, perhaps, the most beautiful of the terrestrial planets. For thousands of years, she has attracted curious glances from scientists of antiquity and modernity, to mere mortal poets. No wonder she bears the name of the Greek goddess of love. But its study adds questions rather than provides any answers.
One of the first observers, Galileo Galilei, observed Venus with a telescope. With the advent of more powerful optical devices such as telescopes in 1610, people began to note the phases of Venus, which closely resembled the phases of the moon. Venus is one of the brightest luminaries in our sky, so at dusk and in the morning, you can see the planet with the naked eye. Watching its passage in front of the Sun, Mikhailo Lomonosov in 1761 examined a thin iridescent rim that surrounded the planet. This is how the atmosphere was discovered. It turned out to be very powerful: the pressure near the surface reached 90 atmospheres!
The greenhouse effect explains the high temperatures of the lower layers of the atmosphere. It is also present on other planets, for example on Mars, due to it, the temperature can rise by 9 °, on Earth - up to 35 °, and on Venus - it reaches its maximum, among the planets - up to 480 ° C.
The internal structure of Venus
The structure of Venus, our neighbor, is similar to other planets. It includes the crust, mantle and core. The radius of the liquid core containing a lot of iron is approximately 3200 km. The structure of the mantle - molten substance - is 2800 km, and the thickness of the crust is 20 km. Surprisingly, with such a nucleus, the magnetic field is practically absent. This is most likely due to the slow rotation. The atmosphere of Venus reaches 5500 km, the upper layers of which are almost entirely composed of hydrogen. Back in 1983, the Soviet automatic interplanetary stations (AMS) Venera-15 and Venera-16 discovered mountain peaks with lava flows on Venus. Now the number of volcanic objects reaches 1600 pieces. Volcanic eruptions testify to the activity of the bowels of the planet, which are locked under thick layers of basalt shell.
Rotation around own axis
Most planets solar system rotate around its axis from west to east. Venus, like Uranus, is an exception to this rule, and rotates in the opposite direction, from east to west. Such non-standard rotation is called retrograde. Thus, a full rotation around its axis lasts 243 days.
Scientists believe that after the formation of Venus, there was a large amount of water on its surface. But, with the advent of the greenhouse effect, the evaporation of the seas began and the release into the atmosphere, which is part of various rocks, carbon dioxide anhydrite. This led to an increase in water evaporation and an increase in temperature in general. After some time, the water disappeared from the surface of Venus and passed into the atmosphere.
Now, the surface of Venus looks like a rocky desert, with occasional mountains and undulating plains. From the oceans, only huge depressions remained on the planet. Radar data taken from interplanetary stations recorded traces of recent volcanic activity.
In addition to the Soviet AMS, the American Magelan also visited Venus. He produced an almost complete mapping of the planet. During the scanning process, a huge number of volcanoes, hundreds of craters and numerous mountains were discovered. According to the characteristic elevations, relative to the average level, scientists have identified 2 continents - the land of Aphrodite and the land of Ishtar. On the first mainland, the size of Africa, there is an 8-kilometer Mount Maat - a huge extinct volcano. The Ishtar mainland is comparable to the size of the United States. Its attraction can be called the 11-kilometer Maxwell Mountains - the highest peaks on the planet. The composition of rocks resembles terrestrial basalt.
In the Venusian landscape, one can find impact craters filled with lava and about 40 km in diameter. But this is an exception, because there are only about 1 thousand of them.
Characteristics of Venus
Weight: 4.87 * 1024 kg (0.815 Earth)
Diameter at equator: 12102 km
Axis Tilt: 177.36°
Density: 5.24 g/cm3
Average surface temperature: +465 °C
Period of revolution around the axis (day): 244 days (retrograde)
Distance from the Sun (average): 0.72 AU e. or 108 million km
Orbital period around the Sun (year): 225 days
Orbital speed: 35 km/s
Orbital eccentricity: e = 0.0068
Orbital inclination to the ecliptic: i = 3.86°
Free fall acceleration: 8.87m/s2
Atmosphere: carbon dioxide (96%), nitrogen (3.4%)
Satellites: no
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 reverse side 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 cloud cover 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.
Concerning chemical composition Venusian atmosphere, then 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 launched on February 12, 1961, but communication with it was soon lost.
Therefore, the first artificial apparatus independently "measured" Venus 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 device.
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.
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 a 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
It is believed that the internal structure resembles that of 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 tectonic movement, which is why we're looking at ancient bark. 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 a 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 should be noted that the temperature highest point Maxwell's grief reaches 380°C and atmospheric pressure reaches 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 closer to the Earth than 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 dark side the planet was marked by a full ring of light, 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 find out more interesting facts, and consider a map of the surface of Venus.
Click on the image to enlarge it
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