What is venus on the planet? The Hathors - Venus Civilization
Venus is the second planet of the solar system and the closest neighbor of the Earth. The distance between Venus and our planet is "only" 108,000,000 million kilometers. Therefore, scientists consider Venus as one of the possible places for settlement. But the day on Venus lasts like an earthly year, and the sun rises in the west. The strangeness of our amazing neighbor will be discussed in this review.
1. Day equals year
A day on Venus is longer than a year. To be more precise, the planet rotates around its axis so slowly that a day on Venus lasts 243 Earth days, and a year - 224.7 Earth days.
2. Visible without a telescope
There are 5 planets that can be seen with the naked eye, not with a telescope. These are Mercury, Venus, Mars, Jupiter and Saturn.
3. Size and orbit
Of all the planets Solar system Venus is most like Earth. Some call it the twin of the Earth, since both planets have approximately the same size and orbit.
4. Floating cities
Recently, scientists have argued that cities that float above the clouds of Venus could be the best choice for potential colonization of another planet. Although hell reigns on the surface of Venus, conditions at an altitude of hundreds of kilometers (temperature, pressure and gravity) are almost ideal for humans.
In 1970, a Soviet interplanetary space probe landed on Venus. It became the first spacecraft to land on another planet, as well as the first to transmit data from there back to Earth. True, this did not last long (only 23 minutes) due to the extremely aggressive situation on the planet.
6. Surface temperature
As you know, the temperature on the surface of Venus is such that nothing living can survive there. And also there is metal snow here.
7. Atmosphere and voice
8. Surface gravity of planets
The surface gravities of Venus, Saturn, Uranus and Neptune are approximately the same. On average, they make up 15% of Earth's gravity.
9. Volcanoes of Venus
Venus has more volcanoes than any other planet in the solar system. To be more precise, there are more than 1,600 of them, most of which are active.
10. Atmospheric pressure
Needless to say, the pressure of the atmosphere on the surface of Venus is also, to put it mildly, unfriendly to people. To be more precise, it is about 90 times higher than the pressure at sea level on Earth.
11. Surface temperature
Hell reigns on the surface of Venus. The temperature here can reach 470 degrees Celsius. Not surprisingly, the Venera 7 probe did not last long.
12. Hurricanes of Venus
Winds on Venus do not lag behind the temperature in extreme. For example, hurricanes with wind speeds of up to 725 km / h are not uncommon in the middle cloud layer.
13. Sunrise in the West
No man-made object has survived on Venus for more than 127 minutes. That is how long the Venera-13 probe lasted.
Scientists are actively developing the space theme today. And recently we talked about.
And the third brightest object in the sky after the Sun and Moon. Sometimes this planet is called sister of the earth, which is associated with a certain similarity in weight 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. Back in the days of the ancient Romans, people already knew that this Venus is one of the 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 she 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 out 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, humanity's knowledge of Venus increased significantly in the second half of the twentieth century. Before the USA and Soviet Union began organizing their missions in the 1960s, scientists still had hope that the conditions under the incredibly dense clouds of Venus might be suitable for life. 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.
The USSR mission of the same name made a significant contribution to the study of both the atmosphere and the surface of Venus. The first spacecraft sent to the planet and flew past the planet was "Venus-1" developed by the Rocket and Space Corporation "Energia" named after S.P. Korolev (today NPO Energia). Despite the fact that communication with this ship, as well as with several other mission devices, 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 spacecraft launched on June 12, 1967, which was able to conduct atmospheric research, was Venera 4. The spacecraft's descent vehicle was literally crushed by the pressure in the planet's atmosphere, but the orbital module managed to make whole line most valuable observations and get the first data on the temperature of Venus, density and chemical composition. The mission made it possible to determine that the planet's atmosphere is 90% carbon dioxide with negligible oxygen and water vapor.
The orbital instruments indicated that Venus has no radiation belts, and the magnetic field is 3,000 times weaker than the Earth's magnetic field. An indicator of the ultraviolet radiation of the Sun on board the ship revealed the hydrogen corona of Venus, the hydrogen content of 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 this and subsequent research, scientists can today distinguish two broad layers in the atmosphere of Venus. The first and main layer is the clouds, which cover the entire planet with an impenetrable sphere. The second is everything below these clouds. The clouds surrounding Venus extend 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 everything back into space. sunlightthat Venus receives.
The second layer, which is under 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 planets in the solar system. Due to the greenhouse effect, the temperature of the layer can reach 480 ° C., which allows the surface of Venus to be heated to the maximum temperatures in our system.
Clouds of venus
Based on observations of the Venus Express satellite, which is overseen by the European Space Agency (ESA), scientists have been able to show for the first time how weather conditions in the thick layers of Venus' clouds 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 planet's surface, but also give clues about what exactly is located on it.
Venus is believed to be very hot due to the incredible greenhouse effect that heats its surface to temperatures of 450 degrees Celsius. The climate on the surface is depressing, and it itself is very poorly lit, as it is covered by an incredibly thick layer of clouds. In this case, the wind that is present on the planet has a speed not exceeding the speed of an easy jogging - 1 meter per second.
However, when viewed from afar, the planet, which is also called the sister of the Earth, looks very different - the planet is surrounded by smooth, bright clouds. These clouds form a 20-kilometer thick layer that sits above the surface and is thus much colder than the surface itself. The typical temperature of this layer is about -70 degrees Celsius, which is comparable to temperatures at the cloud tops of the Earth. In the return layer of the cloud, the weather conditions are much more extreme, the wind blows hundreds of times faster than on the surface and even faster than the rotation speed of Venus itself.
With the help of Venus Express observations, scientists have significantly improved the climate map of Venus. They were able to identify three aspects of the planet's cloudy weather at once: how quickly the winds on Venus can circulate, how much water is contained in the clouds, and how bright these clouds are distributed over the entire spectrum (in ultraviolet light).
“Our results show that all of these aspects — wind, water content and cloud composition — are somehow related to the properties of Venus's surface itself,” said Jean-Loup Berto of the LATMOS observatory in France, lead author of the new Venus Express study. “We used spacecraft observations that spanned six years, from 2006 to 2012, and this allowed us to study the patterns of long-term weather changes on the planet.”
Surface of Venus
Before radar studies of the planet, the most valuable surface data were obtained using the same Soviet space program "Venus". The first spacecraft 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 managed to identify pressure and temperature indicators on the surface, which were 90 ± 15 atmospheres and 475 ± 20 ° C.
1 - descent vehicle;
2 - solar panels;
3 - astro-orientation sensor;
4 - protective panel;
5 - corrective propulsion system;
6 - manifolds of the pneumatic system with control nozzles;
7 - counter of cosmic particles;
8 - orbital compartment;
9 - radiator-cooler;
10 - low directional antenna;
11 - highly directional antenna;
12 - pneumatic system automation unit;
13 - compressed nitrogen cylinder
The subsequent mission "Venera-8" was even more successful - the first samples of the surface soil were obtained. 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, 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 another and made a soft landing on the planet's surface on October 22 and 25, 1975, respectively.
After that, the first radar data were obtained on the Venusian surface. The pictures were taken in 1978, when the first of the American spacecraft, Pioneer Venus, arrived in orbit. The maps created on the basis of the images showed that the surface consists mainly of plains, the cause of the formation of which are powerful lava flows, as well as two mountain regions, called Ishtar Terra and Aphrodite. The data was subsequently confirmed by the Venera 15 and Venera 16 missions, which mapped the planet's northern hemisphere.
The first color images of the surface of Venus and even a sound recording were obtained using the Venera-13 descent module. The module camera took 14 color and 8 black and white photographs of the surface. Also, for the analysis of soil samples, an X-ray fluorescence spectrometer was used for the first time, due 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 photographic images of the planet's surface obtained with the help of the Venus space program are still the only and unique ones, they represent the most valuable scientific material, these photographs could not give a large-scale idea of \u200b\u200bthe planet's relief. After analyzing the results obtained, the space powers focused on the radar study of Venus.
In 1990, he began his work in the orbit of Venus spacecraft called Magellan. He managed to take better quality radar images, which turned out to be much more detailed and informative. For example, it turned out that of the 1000 impact craters that Magellan discovered, none were more than two kilometers in diameter. This led scientists to believe that any meteorite less than two kilometers in diameter simply burned up while passing through the dense Venusian atmosphere.
Due to the dense clouds that envelop Venus, details of its surface cannot be seen with simple photographic means. Fortunately, scientists were able to use the radar technique to obtain the information they needed.
While both photographic equipment and radars work by collecting radiation that is reflected from an object, they have a big difference 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 was clear, since microwave radiation can pass through the planet's thick clouds, while the light needed for photography cannot do so.
Thus, additional studies of the size of the craters have helped shed light on factors that speak of the age of the planet's surface. It turned out that small impact craters are practically absent on the planet's surface, 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 small geological age.
The study of the planet's volcanic activity revealed even more characteristic features of the surface.
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. The second characteristic feature is volcanic formations, which are very numerous and varied. In addition to shield volcanoes that exist on Earth (for example, Mauna Loa), many flat volcanoes have been discovered on Venus. These volcanoes differ from terrestrial ones, as 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 flows out in a single stream, spreading in a circular manner.
Geology of Venus
As with other planets terrestrial groupVenus is essentially made up of three layers: crust, mantle, and core. However, there is something that is very intriguing - the bowels of Venus (as opposed to 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 is 50 kilometers thick, the mantle is 3000 kilometers thick, and the core has a diameter of 6000 kilometers.
In addition, scientists still do not have an answer to the question of whether the planet's core 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. In support of this theory, the researchers cite the fact that the planet is significantly lacking a magnetic field. Simply put, planetary magnetic fields are the result of the transfer of heat from within the planet to its surface, and a necessary component of this transfer is the liquid core. The insufficient power of magnetic fields, according to this concept, indicates that the existence of a liquid core on Venus is simply impossible.
Orbit and rotation of Venus
The most notable aspect of Venus's orbit is its uniform distance from the Sun. The eccentricity of the orbit is only 00678, which means that Venus's orbit is the most circular of all 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 indicates a 3: 2 spin-orbital resonance between Venus and Earth. Proponents of the theory believe that over billions of years, the force of Earth's gravity changed the rotation of Venus to its current state.
Proponents of another concept doubt that the Earth's gravity was large enough to change the rotation of Venus in such a fundamental way. Instead, they link to early period the existence 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 its current orientation when the young planet collided with a large planetesimal. The collision was of such force 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 complete revolution around its axis, the planet needs 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 the 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 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, which makes it visible even on a clear day.
Venus is sometimes referred to as the "morning star" and "evening star". This is due to the fact that representatives of ancient civilizations mistook this planet for two different stars, depending on the time of day.
One day on Venus is longer than one year. Due to its slow rotation on its axis, a day lasts 243 Earth days. A planet's orbit takes 225 Earth days.
Venus is named after the Roman goddess of love and beauty. It is believed that the ancient Romans named it that because of the planet's high brightness, which in turn could have come from the time of Babylon, whose inhabitants called Venus "the bright queen of the sky."
Venus has no satellites or rings.
Billions of years ago, Venus's 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 planet's surface is currently too hot and hostile to support life.
Venus rotates in the opposite direction to the other planets. Most other planets rotate counterclockwise on their axis, but Venus, like, rotates clockwise. This is known as retrograde rotation and may have been caused by a collision with an asteroid or other space object that changed its direction of rotation.
Venus is the most hot planet in the solar system with an average surface temperature of 462 ° C. Also, Venus has no tilt on its axis, 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 movement being too slow. solar wind across the entire surface of the planet.
The Venusian surface is approximately 300-400 million years old. (The age of the Earth's surface is about 100 million years).
The atmospheric pressure of Venus is 92 times stronger than that of Earth. This means that any small asteroids entering Venus's atmosphere will be crushed by the enormous pressure. This explains the absence of small craters on the planet's surface. 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 expected Venus to have a magnetic field similar in strength to Earth's. One possible reason for 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 planet closest to Earth. The distance from our planet to Venus is 41 million kilometers.
Venus Photos
The first and only to date photographic images of the surface of Venus were obtained spaceships of the Soviet space program "Venus". But there are also images of the planet taken by the Akatsuki probe.
Plus
To date, much of the search for life on other planets in the solar system has focused on Mars. This is not surprising, because the red planet is made of minerals, like the Earth, in addition, Mars has an atmosphere, and scientists are almost sure that this planet once had water. But perhaps we should pay attention to another planet - Venus.
Venus today is a very colorful definition of the word uninhabited: the temperature on the planet's surface is so high that it could melt lead, and the atmosphere is made of poisonous sulfuric acid and carbon dioxide. This is not to mention the fact that there is not even a trace of water. But has it always been this way?
Now there is more and more thorium that once Venus was not so inaccessible. American scientists have created several models demonstrating what this planet might once have looked like. Four models of Venus's surface were presented in a recently published article and are based on how much light the planet was receiving and how fast it was orbiting the sun. Today, the "annual" turnover of Venus is 243 days.
Inhabited Venus
According to scientists, there are several scenarios in their theory in which a second planet could support conditions conducive to the formation of life. Between three billion and 715 million years ago, Venus could have been habitable, with oceans, rainfall, and temperatures close to ours.
This is far from the first study to suggest that Venus may have sustained life on its surface, however, none of the earlier theories considered this possibility in such detail and visually. In fact, scientists from the University of Arizona have clearly demonstrated what an inhabited Venus could look like.
Surface conditions
Probably, the intense emission of greenhouse gases into the atmosphere led to the fact that the planet's temperature rose sharply due to the fact that the atmosphere became heavier and heavier, as if enveloping the planet in a thermal blanket that does not allow cooling. In the end, this led to the fact that now the surface of Venus resembles a description of hell.
Today, conditions there are so inhospitable that even the toughest creatures would not be able to survive. The content of carbon dioxide in the atmosphere is 97%, the temperature reaches 470 degrees Celsius, the atmosphere is 90 times heavier than Earth's, and the average pressure is 93 times higher. However, scientists suggest that billions of years ago, things could have been different.
So far, there is no evidence of the existence of water on the surface of Venus. Even possible traces of ancient shores found on Mars can no longer be found on Venus. Most of the planet's present surface was modeled by volcanic activity around 700 million years ago. Even if there was water, its traces have long been swept away by lava and minerals.
However, scientists do not deny the possibility of existence warm oceans on Venus. According to them, there, as well as on Earth, there could be water in contact with stones and organic molecules, which, at a suitable temperature and the presence of light, irreversibly undergo chemical evolution.
Quick reference
Mercury - the planet closest to the Sun. The average distance between Mercury and the Sun is 58 million kilometers. The planet has a highly elongated orbit. A year on Mercury lasts 88 days. The planet has a highly rarefied helium atmosphere. The pressure created by such an atmosphere is 500 billion times less than the air pressure at the Earth's surface.
Venus - the brightest object of the earth's sky after the Sun and the Moon. Venus makes a complete revolution around the Sun in 225 days. The period of rotation around the axis is 243 days, i.e. the length of the day is the largest among the planets. The atmosphere of Venus is 96.5% carbon dioxide and 3.5% nitrogen.
Necessary equipment
In terms of equipment, observing Mercury and Venus is not fundamentally different from observing other planets. However, there are some nuances. For example, achromatic refractors are of little use for observing Venus, which burden the image with large chromatism, which is especially manifested due to the dazzling brilliance of the planet. It will not be superfluous to have an equatorial mount or a mount equipped with Go-To, since the observation of the lower planets can and should be carried out in the daytime. But the difficulty of finding a planet during the daytime makes it nearly impossible to use conventional, alt-azimuth mounts.
The details on the surfaces of Mercury and Venus are barely perceptible in visual observations, and the quality of all the optical assemblies of the telescope should not be in doubt. It is recommended to have quality planetary eyepieces in stock - orthoscopes and monocentrics.
A set of color filters will also come in handy. Orange, red, and dark red (useful on large telescopes) filters will help improve the contrast of planets when viewed in daytime and twilight skies. Green, purple and blue highlight dark details on planetary disks.
Attention! When making daytime observations of Mercury or Venus, do not look at the Sun through the telescope eyepiece or optical finder under any circumstances! For more information about observing the Sun through a telescope, read the instructions for the telescope. Avoid accidentally entering the sun into the telescope's field of view. Even a quick glance at the Sun can damage your eyesight.
Mercury
When to observe Mercury
Mercury has a reputation among observers as an "elusive planet." The fact is that among all the planets, the duration of its visibility is the smallest. Since in its visible movement across the sky, Mercury does not move far from the Sun, residents of the middle northern latitudes (Russia and the CIS countries, Europe, England, USA, etc.) have no opportunity to see the planet in the dark. On the contrary, observers Southern hemisphere sometimes they have the opportunity to capture Mercury after the onset of the astronomical night.
The most favorable periods for observing Mercury are at the moments of its greatest elongation (distance from the Sun), and when the planet is at its highest above the horizon during sunset or sunrise. In mid-northern latitudes, such moments occur in the spring during the period of eastern elongation, when Mercury is visible in the evening, or during the autumn periods of its western elongation, when the planet is visible in the morning.
Observations of Mercury
Most likely, the first observation of Mercury will disappoint you a little. Compared to Jupiter, Saturn and the Moon, the planet is, to put it mildly, unattractive. Mercury is a planet for sophisticated observers who love to set themselves difficult tasks and strive to achieve great results.
Moreover, many experienced astronomers have never observed Mercury. But if you like to spend hours looking at dim and unremarkable galaxies, perhaps Mercury will be new, exciting fun for you.
Observing Mercury with the naked eye or through binoculars
Contrary to the common misconception, Mercury is quite easy to find in the sky with the naked eye. As a rule, the chances of success are quite high if you search for a planet within a week before and after its greatest elongation. They increase significantly if the atmosphere is calm and the observation is not interfered with by tall buildings and city smog.
In the spring, during the period of evening visibility, Mercury is visible with the naked eye half an hour after sunset, not high above the western part of the horizon. Depending on the terrain and the transparency of the atmosphere, the planet can be observed for about an hour in the twilight sky. Similarly, in the fall, when the morning visibility sets in, Mercury can be viewed 30 minutes after its rise and be contemplated with the naked eye for an hour, until it disappears in the rays of the rising sun.
During favorable periods, the brightness of Mercury reaches -1.3 magnitude, which is only 0.1 less than that of Sirius, the brightest star in the earth's sky. It is worth noting that the low altitude above the horizon and, as a result, a thick and bubbling layer of air standing in the path of light from the planet, makes Mercury twinkle like other stars. Many observers note the planet has a pink or pale pink hue - pay attention to this on your next observation of Mercury.
It is much easier to see Mercury through binoculars, especially in the first minutes after sunset, when the sky is still quite bright. Of course, it will not be possible to see the phases of the planet through binoculars, and nevertheless, this is an excellent tool for finding a planet and observing such beautiful phenomena as the approach of Mercury with other planets, as well as with bright stars and the Moon.
Telescope observations of Mercury
Typically, for telescopic observations, Mercury is available for five weeks around its best visibility periods. But it's worth mentioning right away that observing Mercury is not an easy task. As mentioned above, the low position of the planet above the horizon creates obstacles for its observation. Get ready for the fact that the image of the planet will constantly "sausage", and only in rare moments, for a split second, the picture calms down and allows you to see some interesting details.
The most obvious feature is the phases of Mercury, which can be easily seen with an 80mm telescope. True, this requires accelerating the magnification of the telescope to at least 100x. Close to maximum elongation, i.e. the best time to observe the planet, the visible disk of Mercury is 50% illuminated (half of the disk). It should be noted that it is almost impossible to consider the phase when the planet is illuminated by less than 30% or more than 70%, since at this time Mercury is too close to the Sun.
If it is not so difficult to discern the phases of Mercury, then distinguishing the details on its disk is not a task for the faint of heart. There is a lot of conflicting information about the observation of various dark spots on its surface. Some observers report that they can see details through medium-sized telescopes, while others cannot see anything on the planet's disk. Of course, success depends not only on the size of the telescope and its optical qualities, but also on the experience of the observer, as well as on the observation conditions.
Sketch. Dark details on the surface of Mercury. Telescope ШК 8 "
Near the moments of the greatest elongation of Mercury, in a 100-120-mm telescope, under good atmospheric conditions, one can see slight darkening along the terminator line. However, it is quite difficult for the untrained eye to see the finest details on its surface, so experienced observers in this case have a better chance of success.
With a telescope with a lens diameter of more than 250 mm, you can try to see large darkening of the surface far from the terminator. This fun and extremely challenging activity can be a good test of your observational skills.
Venus
When to observe Venus
Venus is more accessible to observation than Mercury. Despite the fact that, like Mercury, Venus does not move far from the Sun, the apparent angular distance between them can reach 47 °. During the period of optimal visibility, Venus can be observed for several hours after sunset as the "Evening Star" or before sunrise as the "Morning Star". For residents of the Northern Hemisphere best time for observations it falls on the eastern elongation, when on spring evenings the planet can be observed until midnight.
In periods close to the eastern or western elongation, the planet is located high above the horizon and has a high brightness, which favorably affects the observation conditions. As a rule, the duration of the best visibility is about a month.
Observations of Venus
Observing Venus with the naked eye during the day
The easiest way to observe Venus with the naked eye is to locate the planet as it rises in the morning sky and keep it in sight after sunrise for as long as possible. In favorable periods of visibility and in the presence of an ideal state of the atmosphere, Venus can be kept in sight for quite a long time.
The chances of success are increased by blocking the Sun with an artificial or natural barrier. For example, finding a convenient place so that a tall tree or building could obscure the bright Sun, but not obscure the planet. Naturally, the daytime search for Venus should begin with accurate information about its position in the sky and distance from the Sun. Such data can be obtained using any planetarium program, for example StarCalc.
Of course, it is quite difficult to see in the daytime sky a barely noticeable tiny patch of light that is almost not distinguished from the surrounding background, which is Venus. However, there is one trick that can help to capture this ghostly glow: when starting to search for a planet, first of all, you should look for a while at the distant horizon, and then direct your gaze to the supposed place in the sky where Venus should be located. Since the eyes have the ability to maintain focus for a short period of time (in this case, focusing to infinity), your chances of seeing the planet increase.
Observing Venus with binoculars
Binoculars are an excellent tool for finding Venus and making its simplest observations. Thanks to the large field of view of binoculars, it becomes possible to observe the approach of planets between themselves and with the Moon. Large astronomical binoculars - 15x70 and 20x100 - are quite capable of showing the phases of Venus when its visible disk is more than 40 "".
It is much easier to find Venus through binoculars during daylight hours. But be careful: even an accidental hit of the Sun in the field of vision can damage your eyes, which will lead to a complete loss of vision! The search for Venus is best done in fine weather, when the sky is blue and distant structures are visible on the horizon, which indicates a high transparency of the atmosphere. As a guide when searching for a planet, you can choose the Moon, which is usually easily visible in a bright sky. To do this, in advance, using the planetarium program, determine the day and time when the Moon and Venus will be at a short distance from each other and, taking binoculars with you, go hunting.
Phases of Venus. Photographer Chris Proctor
Observing Venus through a telescope
Daytime observations of Venus
Even in a small telescope, the dazzling glow of Venus reduces the overall contrast of the image, making it difficult to see its phases, and also nullifies all efforts to see the finest details of the surface.
One way to reduce the brightness of the planet is to make observations during the day. The telescope allows you to observe Venus in the daytime sky almost all year round. Only for two weeks before and after its upper conjunction, the planet is inaccessible for observation due to its excessive proximity to the Sun.
Owners of Go-To telescopes can easily point the telescope to Venus using the telescope's Sun alignment method. How to do this is described in detail in the telescope user manual.
Another way to find Venus is to use a telescope on an equatorial mount that has alignment circles. To do this, carefully align the mount, then point the telescope at the Sun, taking the necessary precautions (use a filter specially designed for observing the Sun or project the image onto a sheet of paper). Then, align the coordinate circles with the previously calculated equatorial coordinates of the Sun (Ra and Dec). The exact coordinates of the Sun and Venus at a given time can be calculated in advance using the planetarium program. After aligning with the Sun, slowly begin to move the telescope tube until the coordinates on the setting circles match the coordinates of Venus. Using the search eyepiece, look through the telescope and find the planet. It should be noted that it is much easier to view Venus if you carefully adjust the focus of the telescope for distant objects in advance.
Once the planet has been found, a higher magnification can be applied. An orange or red filter can be helpful, which can enhance the contrast between Venus and the sky background, as well as highlight the subtle details of the cloud cover. In the period close to the lower conjunction, Venus looks like a narrow sickle. At such moments, one can notice the appearance of the so-called horns of Venus, which outline the disk of the planet with a thin light edging. This phenomenon is caused by the scattering of sunlight in the planet's atmosphere.
A typical view of Venus through a small telescope. Sketch by Evan Bruce
Night observations of Venus
Despite the fact that daytime observations of Venus have several advantages, many astronomy lovers prefer to observe the planet in the twilight or night sky. Of course, at this time of day there are no problems with detecting a planet in the sky, which is an obvious plus. However, there are plenty of minuses. As mentioned above, the main enemy of the observer is the dazzling brilliance of Venus, which prevents the detection of the finest details in the planet's cloud cover. However, this disadvantage can be dealt with by using a polarizing filter with variable density.
Another disadvantage is the small height of the planet above the horizon. As a rule, even in the best periods of visibility, in the dark, the height of Venus above the horizon does not exceed 30 °. And as you know, it is advisable to observe any object when its height is more than 30 °. At this height bad influence atmosphere for image quality is minimized.
In general, speaking about the observation of Venus and taking into account the peculiarities of its visibility, this bar can be lowered. But it should be borne in mind that observations of the planet during a period when its height above the horizon is less than 20 ° are not desirable.
Observing dark patterns in the clouds of Venus
Often, the disk of Venus appears to the observer as uniform, grayish-white and without any details. Sometimes, under good viewing conditions, a darkening along the terminator line can be seen. Even less often, some astronomy lovers manage to see dark formations with bizarre shapes. What affects the visibility of parts? At the moment, there is no clear and unambiguous answer. Most likely, a combination of factors: the observation conditions, the quality of the equipment, and the peculiarities of vision. Let us dwell on the latter in more detail.
Decades ago, it was suggested that some observers' eyes are more sensitive to the ultraviolet spectrum, allowing them to see dark streaks and formations on the planet. This assumption was later confirmed by photographs taken in the ultraviolet spectrum, which showed the presence of details not visible in conventional photographs. Again, self-deception of the observer should not be discounted. The fact is that dark features are extremely elusive - it's easy to convince yourself of their presence just because you expect to see them.
It is also difficult to answer the question of the minimum telescope required to observe the details of the cloud cover. Some observers claim that they see them in 100-mm telescopes, while others cannot see them in larger ones. Some observers are able to see darkening with a blue, purple or yellow filter. Therefore, regardless of the equipment you have, do not stop trying to find interesting features, train your eyes, and you will definitely be lucky.
There is the following classification of dark features:
Ribbon.Dark, parallel stripes. They go perpendicular to the edge of the horns.
Radial. Dark stripes extending radially from the sun point (the place where the sun's rays hit at right angles).
Wrong. They have an indistinct shape, can be both elongated and almost straight.
Amorphous... Chaotic darkening, shapeless and not amenable to any description.
White (bright) spots on Venus
Sometimes it is possible to observe bright spots near the poles of the planet. The so-called polar spots can last for several weeks and are usually characterized by slow onset and equally slow disappearance. Often, spots appear near the South Pole, less often at the North Pole.
Sketches of Venus in a 100mm reflector. Dark and light formations and irregularities of the terminator are visible.
Anomalies
Schroeter effect
The so-called Schroeter effect consists in delaying or advancing the onset of the moment of dichotomy (phase 0.5) by several days relative to preliminary calculations. Observed in the lower planets (Mercury and Venus). The reason for this phenomenon lies in the scattering of sunlight along the terminator of the planet.
Ash light
Another interesting illusion occurs when Venus has a narrow sickle phase. Sometimes during these periods one can notice a slight glow of an unlit part of the planet.
Rough contour
Combinations of dark and bright details that appear more clearly near the terminator line create the illusion of unevenness. This phenomenon is difficult to see visually, but, as a rule, it shows up well in photographs of Venus. The planet becomes like a piece of cheese, as if neatly gnawed by mice from the edge (near the terminator).
Venus is the second planet in the distance from the Sun (the second planet of 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's neighbors are Mercury and Earth.
The structure of Venus is a subject of controversy. The most likely is: an iron core with a mass of 25% of the mass of the planet, the mantle (extending 3300 kilometers into the interior of the planet) and crust 16 kilometers thick.
A significant part of the surface of Venus (90%) is covered with solidified basalt lava. It contains vast hills, the largest of which are comparable in size to terrestrial 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 the Moon.
Orbit of Venus
The average distance from Venus to the Sun is just under 108 million kilometers (0.72 astronomical units).
Perihelion (orbital point closest to the Sun): 107.5 million kilometers (0.718 astronomical units).
Aphelios (orbital point farthest from the Sun): 108.9 million kilometers (0.728 astronomical units).
The average speed of Venus's orbital motion 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 terrestrial.
The distance from Venus to Earth ranges from 38 to 261 million kilometers.
The direction of rotation of Venus is opposite to the direction of rotation of all (except Uranus) planets in the solar system.
