How to observe Mercury and Venus. Visibility and position of the planets this June When you can see Venus with the naked eye
Venus is the second planet in the solar system and Earth's closest neighbor. Between Venus and our planet, the distance is “only” 108,000,000 million kilometers. Therefore, scientists consider Venus as one of the possible places for settlement. Except that a day on Venus lasts like an Earth year, and the sun rises in the west. The oddities of our amazing neighbor will be discussed in this review.
1. A day equals a 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 and not with a telescope. These are Mercury, Venus, Mars, Jupiter and Saturn.
3. Size and orbit
Of all the planets in the solar system, Venus is the most Earth-like. Some call it Earth's twin because both planets are roughly the same size and orbit.
4. Floating cities
Recently, scientists have argued that cities that will float above the clouds of Venus may 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 ship to land on another planet, and also the first to transmit data from there back to Earth. True, it 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.
7. Atmosphere and voice
8. Surface gravitations of planets
The surface gravities of Venus, Saturn, Uranus and Neptune are approximately the same. On average, they make up 15% of the 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 1600 of them, and most of them 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
On the surface of Venus, hell reigns. The temperature here can reach 470 degrees Celsius. It is not surprising that the Venera-7 probe lived for such a short time.
12 Venus Hurricanes
The winds on Venus do not lag behind the temperature in terms of extremeness. For example, in the middle layer of clouds, hurricanes with wind speeds up to 725 km / h are not uncommon.
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 today are actively developing the space theme. And recently they talked about.
Mercury is called "elusive" because it is difficult to observe. This planet, the closest to the Sun, often hides in its rays, and in our sky does not move far from the Sun - a maximum of 28 degrees, since Mercury's orbit is located inside the earth. Mercury is always in the sky, either in the same constellation as the Sun, or in a neighboring one. Usually Mercury is visible against the backdrop of dawn and is difficult to find in a bright sky. The best time to observe Mercury is when it is farthest away from the Sun in the sky.
Austria On the same days - on the border of the constellations of Sagittarius and Capricorn - Mercury is visible next to Venus - it is also bright (comparable in brightness to the brightest stars in the sky), but the evening dawn can be brighter than it and Mercury will most likely be found only with binoculars - find Venus with your eye, point binoculars at it and Mercury will be in the same field of view with it. This is a fairly rare event and must be seen. The approach of Venus to Mercury will last until mid-January 2015.
USA The angular removal of a planet from the Sun is called elongation. If the planet is removed from the Sun to the east - this is the eastern elongation, if to the west - the western. At eastern elongation, Mercury is visible in the west low on the horizon in the rays of the evening dawn, shortly after sunset, and sets some time after it. At western elongation, Mercury is visible in the east in the morning against the backdrop of dawn, shortly before sunrise. This couple is also visible from the territory of Russia. Astronomers write. that they should be visible within an hour and they set around seven in the evening. On January 15, Mercury will be at its greatest eastern elongation, moving away from the Sun by 19 degrees. And the days closest to this date are the most favorable for its observation. After sunset, Mercury will be above the horizon for almost two hours. As a bright star, it will be visible in the southwest in the constellation of Capricorn, low on the horizon. Find it without difficulty will help Venus. This brightest planet, attracting attention with its bright brilliance, shines in the evenings over the western horizon. The bright star to the right of it is Mercury.
Japan After January 16, 2015, Venus and Mercury will part ways in the sky. Mercury will begin to return to the Sun, describing a loop in the celestial sphere, and Venus will continue to move away from the daylight and the duration of its visibility will increase every day.
It is said that Napoleon was quite annoyed and angry when, one afternoon, during his trip to the Luxembourg Palace, the audience no longer looked at him, but at a star shining brightly in the daytime sky. This wonderful "star" was planet Venus.
This really does happen. It is known that in 1750, and also in Paris, Venus was visible in the daytime sky, which led the inhabitants of the city and the surrounding area into amazement and fear. In 1799, General Bonaparte, returning from the conquest of Italy, also saw a wondrous heavenly diamond above his head. Perhaps then he believed in "his star."
Camille Flammarion's Popular Astronomy says that in ancient times, Aeneas, returning from Troy, saw Venus shining at its zenith during the day.
And here is what another French astronomer, Francois Arago, wrote in the book “Public Astronomy”: “... In 1716, the London mob considered the appearance Venus day for something wonderful. This gave Halley a reason to calculate the positions in which the planet appears in its largest volume ... "
Visibility conditions for Venus
But really, what are the conditions for the visibility of Venus? Particularly during the day? The best visibility - evening or morning - when Venus is in. For Venus, the maximum value is 48° (in rare cases, 52°). However, not at every elongation Venus is visible in the sky well enough. The best evening visibility is in February, March, April. Morning visibility during western elongation is best in autumn: in August, September, October. It is at this time of the year that it happens to be observed during the day.
“... Then a sign will appear in heaven, the star is bright, standing above the church, shining all day ...” - we read, for example, in the Pskov Chronicle. It was Venus on August 25, 1331. On that date, she was in western elongation, that is, she was a morning star, and her brightness was approaching the maximum possible.
Venus is at its brightest approximately 36 days before and 36 days after inferior conjunction. At maximum brightness, the apparent stellar magnitude of Venus reaches minus 4.6m and more.
It happens that from the bright Venus, objects on Earth give a shadow.
Of the nine planets in the solar system, Venus largest albedo(reflectivity) - 0.77, which is probably due to the carbon dioxide atmosphere of the planet. But Venus also receives about twice as much sunlight as the Earth. That is why, even on Mars, Venus is the brightest light in the sky after the Sun and the Martian moons.
Now a few words about the phases of Venus. It is known that people with exceptionally sharp eyesight can see the phases of Venus even with the naked eye. Like, for example, the mother of the famous mathematician Gauss. He invited his mother to look at Venus through an astronomical tube, he thought to impress with an unprecedented sight: Venus in the form of a sickle. However, he himself had to be amazed.
The woman only asked why it is just with her eye that she sees a sickle turned in one direction, and through a telescope - in the other ...
The moon is known to be at its brightest during the full moon phase. But the maximum brightness of Venus falls on the period when about 30 percent of its surface is illuminated. This is about halfway between its greatest elongation and inferior conjunction.
The entire sequence, the entire cycle of its phases, Venus passes almost exactly 5 times in 8 years. In astronomical language, it sounds like this: 5 synodic revolutions of Venus are made in 8 years.
Indeed: the average synodic Venus period about 584 days. If 5 x 584 = 2920 days. And 8 periods of the Earth's revolution around the Sun - 8 x 365.25 = 2922 days. That is a difference of only 2 days! That is why every 8 years the conditions for the visibility of Venus are almost exactly the same. That is, every 8 years Venus appears almost exactly in the same phase, almost exactly in the same place in the sky.
The diameter of the planet in different phases is not the same: a narrow sickle is much larger in diameter than a full disk. The reason is that in different phases the planet is removed from us at different distances (from 108 to 258 million kilometers). In the immediate vicinity of the Earth, Venus faces us with its unlit side, so we never see its largest phase. A full disk is visible only from the greatest distance. Venus is brightest for us when its angular diameter is 40″ and the angular width of the sickle is 10″. Then it shines 13 times brighter than Sirius - the brightest star in the earth's sky.
That is why on ancient steles, seals, amulets, Venus was painted with 8 rays. And the number 8 was considered sacred by many ancient peoples.
The Babylonians at the end of the III millennium BC. e. there was a calendar based on an 8-year cycle. "8 great deities of the primordial time" knew the Egyptians.
In Homer's Odyssey, the eighth year is repeatedly mentioned as a turning point, bringing decisive changes. In Greece, it was generally believed that significant events usually occurred in the eighth year. Orestes takes revenge for the murder of his father, committed 8 years ago.
According to one version of the myth of Theseus, the Athenians sent a terrible tribute to the monster Minotaur to Crete every 8 years.
The Thracians called the festival in honor of the god of light and arts Apollo the “eight years”. And in ancient Thebes, a holiday in honor of Apollo was celebrated every 8 years. The ancient Aztecs held a festival of "absorption of water and bread" every 8 years. The laws of Moses contain an indication: "And you will sow in the eighth year ..." The list could be continued. But even this is enough to understand the significance of Venus in the life of ancient peoples! Venus was by far the first of the "wandering stars" that man singled out because of its conspicuous brightness.
However, initially the ancient peoples took the “morning and evening stars” for two different ones. Morning Venus was called Phosphoros by the ancient Greeks, and Lucifer by the Latins, both words meaning "carrying light."
BUT evening Venus called - Vesper (Hesper), that is, "west", "evening".
The word Vesper in modern times means "evening prayer" in many languages.
Instruction
Five were discovered in ancient times, when there were no telescopes. The nature of their movements across the sky is different from movement. Based on this, people have separated from millions of stars.
There are inner and outer planets. Mercury and Venus are closer to the Sun than Earth. Their location in the sky is always close to the horizon. Accordingly, these two planets are inner planets. Also, Mercury and Venus seem to follow the sun. Nevertheless, they are visible to the naked eye at the moments of maximum elongation, i.e. during the maximum angle from the Sun. These planets can be seen at dusk, shortly after sunset or in the wee hours. Venus is much larger than Mercury, much brighter and easier to spot. When Venus appears in the sky, no star can compare with it in brightness. Venus shines with white light. If you look closely at it, for example, with binoculars or a telescope, you will notice that it has different phases, like the moon. Venus can be observed in the form of a sickle, decreasing or increasing. In early 2011, Venus was visible for about three hours before dawn. It will be possible to observe it again with the naked eye from the end of October. It will be visible in the evening, in the southwest in the constellation of Libra. Toward the end of the year, its brightness and duration of the visibility period will increase. Mercury is mostly visible during twilight and is quite difficult to spot. For this, the ancients called him the god of twilight. In 2011 it can be seen from the end of August for about a month. The planet will first be visible in the morning hours in the constellation of Cancer, and then move into the constellation of Leo.
The outer planets are, respectively, Mars, Jupiter and Saturn. They are best observed during moments of confrontation, i.e. when the Earth is on the same straight line between the planet and the Sun. They can stay in the sky all night. During the maximum brightness of Mars (-2.91m), this planet is second only to Venus (-4m) and Jupiter (-2.94m). In the evening and in the morning, Mars is visible as a red-orange "star", and in the middle of the night it changes light to yellow. In 2011, Mars will appear in the sky in the summer and disappear again at the end of November. In August, the planet can be seen in the constellation of Gemini, and by September it will move into the constellation of Cancer. Jupiter is often seen in the sky as one of the brightest stars. Despite this, it is interesting to observe it with binoculars or a telescope. In this case, the disk surrounding the planet and the four largest satellites become visible. The planet will appear in June 2011 in the eastern part of the sky. Jupiter will get closer to the Sun, gradually losing its brightness. Closer to autumn, its brightness will begin to increase again. At the end of October, Jupiter will enter opposition. Accordingly, the autumn months and December are the best time to observe the planet.
From mid-April to early June, Saturn is the only planet visible to the naked eye. The next favorable period for observing Saturn will be November. This planet moves slowly across the sky and will be in the constellation Virgo all year round.
Venus comes closer to Earth than any other planet. But the dense, cloudy atmosphere does not allow you to directly see its surface. Radar images show a very wide variety of craters, volcanoes and mountains.
Surface temperatures are hot enough to melt lead, and this planet may have once had extensive oceans.
Venus is the second planet from the Sun, which has an almost circular orbit, which it bypasses in 225 Earth days at a distance of 108 million km from the Sun. Rotation around the axis of Venus takes 243 Earth days - the maximum time among all the planets. Venus rotates around its axis in the opposite direction, that is, in the opposite direction to its orbit. This slow and reverse rotation means that, as seen from Venus, the Sun rises and sets only twice a year, since the Venusian days are equal to 117 of ours. Venus approaches the Earth at a distance of 45 million km - closer than any other planet.
Venus is only slightly smaller than Earth, and has almost the same mass. For these reasons, Venus is sometimes referred to as Earth's twin or sister. However, the surface and atmosphere of these two planets are completely different. The Earth has rivers, lakes, oceans and the atmosphere we breathe. Venus is a scaldingly hot planet with a dense atmosphere that would be fatal to humans.
Before the start of the space age, astronomers knew very little about Venus. Dense clouds prevented them from seeing the surface through telescopes. The spacecraft managed to pass through the atmosphere of Venus, which consists mainly of carbon dioxide with impurities of nitrogen and oxygen. Pale yellow clouds in the atmosphere contain droplets of sulfuric acid that fall on the surface as acid rain.
Finding Venus in the sky is easier than any other planet. Its dense clouds perfectly reflect sunlight, making the planet bright. Since the orbit of Venus is closer to the Sun than the Earth's, Venus never moves far from the Sun in our sky. Every seven months, for several weeks, Venus is the brightest object in the western sky in the evening. It is called the "evening star". During these periods, the sawn brilliance of Venus is 20 times greater than the brilliance of Sirius, the brightest star in the northern sky. Three and a half months later, Venus rises three hours before the Sun, becoming the brilliant "morning star" of the eastern sky.
You can observe Venus about an hour after sunset or an hour before sunrise. The angle between Venus and the Sun never exceeds 47°. For two or three weeks near these points, Venus cannot be missed, unless the sky is clear. If you first see Venus in the pre-dawn sky during the period of greatest western elongation, then you will be able to distinguish it later, even after sunrise, it is so bright. If you use binoculars or a telescope, take the necessary precautions so that the Sun does not accidentally enter your field of vision.
It is easy to see that Venus, like Lupe, has phases. At its points of greatest elongation, the planet looks like a tiny moon in its half-disk phase. As Venus approaches the Earth, its apparent size increases slightly every day, and its shape gradually changes to a narrow crescent. But no features of the planet's surface can be seen due to dense clouds.
Transit of Venus across the disk of the Sun
It is very rare for Venus to pass exactly between the Earth and the Sun. These passages were used in the 18th century. to determine the size of the solar system. Noting the difference in time between the beginning and end of the passage when observed from different points on the Earth, astronomers estimated the distance between the Earth and Venus. Captain Cook's third voyage in search of discovery (1776-1779) included observing the passage. Venus will next cross the solar disk in 2004.
Phases of Venus
Galileo was the first to observe the phases of Venus in 1610. From the similarity with the phases of the Moon, he concluded that the orbit of Venus is closer to the Sun than the orbit of the Earth. His observations of Venus proved that the Sun is at the center of our solar system. By observing the phases of Venus once every few days for about a month, you can calculate whether this planet is approaching us or moving away from us.
hot world
The atmosphere of Venus is extremely hot and dry. The surface temperature reaches its maximum at about 480°C. The atmosphere of Venus contains 105 times more gas than the atmosphere of Earth. The pressure of this atmosphere near the surface is very high, 95 times higher than on Earth. Spaceships have to be designed to withstand the crushing, crushing force of the atmosphere. In 1970, the first spacecraft to land on Venus could only endure the sweltering heat for about one hour, just long enough to send back data on surface conditions to Earth. Russian aircraft that landed on Venus in 1982 also sent color photographs of sharp rocks to Earth.
Due to the greenhouse effect, Venus is terribly hot. The atmosphere, which is a denser blanket of carbon dioxide, retains the heat that comes from the sun. As a result, such an amount of thermal energy accumulates that the temperature of the atmosphere is much higher than in an oven.
On Earth, where the amount of carbon dioxide and the atmosphere is small, the natural greenhouse effect raises the global temperature by 30 "C. And on Venus, the greenhouse effect raises the temperature by another 400". Studying the physical consequences of the strongest greenhouse effect on Venus, we can imagine the results that the accumulation of excess heat on the Earth, caused by the growing concentration of carbon dioxide in the atmosphere due to the burning of fossil fuels - coal and oil, can lead to.
Venus and Earth in ancient times
4.5 billion years ago, when the Earth first formed, it also had a very dense atmosphere of carbon dioxide - just like Venus. This gas, however, dissolves in water. Earth was not as hot as Venus because it is farther away from the Sun; as a result, rains washed carbon dioxide out of the atmosphere and sent it to the oceans. From the shells and bones of marine animals, rocks such as chalk and limestone arose, which included carbon and oxygen. In addition, carbon dioxide was extracted from the atmosphere of our planet and during the formation of coal and oil. There is not a lot of hearth in the atmosphere of Venus. And due to the greenhouse effect, the temperature of the atmosphere exceeds the boiling point of water up to an altitude of about 50 km. Venus may have once had oceans, but if there were, they have long since boiled away.
Surface of Venus
To study the nature of the surface of Venus under a thick layer of clouds, astronomers use both interplanetary ships and radio waves. More than 20 US and Russian spacecraft have already been heading to Venus, more than any other planet. The first Russian ship was crushed by the atmosphere. However, in the late 1970s and early 1980s, the first photographs were taken, in which formations of hard rocks are visible - sharp, sloping, crumbling, small crumbs and dust. - the chemical composition of which was similar to the volcanic rocks of the Earth.
In 1961, scientists sent radio waves to Venus and received a reflected signal on Earth, measuring the speed of the planet's rotation around its axis. In 1983, the Veiera-15 and Venera-16 spacecraft entered orbit around Venus.
Using radar, they built a map of the northern hemisphere of the planet up to parallel 30". Even more detailed maps of the entire surface with details up to 120 m in size were obtained in 1990 by the Magellan spacecraft. With the help of computers, radar information was turned into images similar to photographs, where volcanoes, mountains and other details of the landscape are visible.
impact craters
Magellan transmitted to Earth beautiful images of the huge Venusian craters. They arose as a result of impacts of giant meteorites that broke into the atmosphere of Venus to its surface. Such collisions released the liquid lava contained within the planet. Some meteorites exploded in the lower atmosphere, creating shock waves that formed dark round craters. Meteorites passing through the atmosphere fly at a speed of about 60,000 km/h. When such a meteorite hits the surface, solid rock instantly turns into hot steam, leaving a crater in the ground. Sometimes lava after such an impact finds its way up and flows out of the crater.
Volcanoes and lava
The surface of Wpori is covered with hundreds of thousands of volcanoes. There are several very large ones: 3 km high and 500 km wide. But most of the volcanoes are 2-3 km across and about 100 m high. The outpouring of lava on Venus takes much longer than on Earth. Venus is too hot for ice, rain or storms, so there is no significant weathering. This means that volcanoes and craters have hardly changed since they formed millions of years ago. In the photographs of Venus taken from the Magellan, we see such an ancient landscape that you will not see on Earth - and yet it is younger than on many other planets and magnifiers.
Apparently, Venus is covered with solid rocks. Hot lava circulates beneath them, causing tension in the boggy surface layer. Lava is constantly erupting from holes and fissures in solid rock. In addition, volcanoes all the time emit jets of small droplets of sulfuric acid. In some places, thick lava, gradually oozing, accumulates in the form of huge puddles up to 25 km wide. In other places, huge paw bubbles form domes on the surface, which then fall off.
On Earth, it is not easy for geologists to find out the historian) of our planet, because the floor is constantly eroded by wind and rain. Venus is of great interest to scientists for the reason that its surface is similar to ancient fossil layers. The details of its landscape, discovered by Magellan, are hundreds of millions of years old.
Volcanoes and lava flows are preserved in an unchanging saw on this dry planet, the world of which is the closest to ours.
