Day and year on Mercury. How long does day last on Mercury? Planets of the Solar System: How many year lasts there
As soon as the Mariner-10 automatic station sent from the land finally reached the almost unemployed Planet of Mercury and began its photographing, it became clear that the earthlings expect large surprises, one of which is an extraordinary, separation similarity of the surface of Mercury with the moon. The results of further studies have plunged researchers to even greater amazement - it turned out that Mercury has much more common with the Earth than with her eternal satellite.
Illusory relationship
From the first "Mariner-10" transitions, the pictures really watched the moon and at least her twin - on the surface of Mercury turned out to be many crater, which at first glance looked completely identically moon. And only thorough studies of the pictures made it possible to establish that the seal areas around the lunar craters, isolated from the material thrown at the crater-forming explosion, one and a half times wider Mercurian - with the same size of the craters. It is explained by the fact that big power Severity on Mercury prevented a longer soil scaly. It turned out that in Mercury, like on the moon, there are two main types of terrain - the analogues of the lunar continents and the seas.
Mainland areas are the most ancient geological formations of Mercury, consisting of sector-bequeatrated sectors, intercratera plains, mountain and hilly formations, as well as from barlast areas covered with numerous narrow ridges.
The smooth plains of Mercury are considered the analogues of the Merkuria, which are younger in age than the continents, and somewhat darker of continumous formations, but still not so dark as the lunar seas. Such areas on Mercury are concentrated in the area of \u200b\u200bthe heat plains - the unique and largest on the planet of the ring structure with a diameter of 1,300 km. It did not accidentally receive its name of the plain - the meridian 180 ° h passes through it. D., It is he (or the opposite meridian 0 °) is located in the center of the hemisphere of Mercury, which is drawn to the Sun, when the planet is at minimal from the luminous distance. At this time, the surface of the planet is stronger than all in the data areas of the meridians, and in particular in the area of \u200b\u200bthe plains of heat. It is surrounded by a mountainous ring, which limits the huge round depression formed at an early stage of the geological history of Mercury. Subsequently, this depression, as well as neighboring areas, were flooded with lavami, when the smooth plains arose.
On the other side of the planet, exactly opposite the depressions, in which the plain heat is located, there is another unique formation - a hilly-line terrain. It consists of numerous large hills (with a diameter of 5-10 km and a height of up to 1-2 km) and is crossed by several large straightforward valleys, clearly educated on the lines of fault faults of the planet. The location of this area in the opposite of the heat plain served as the basis for the hypothesis that the hilly-line relief was formed due to the focusing of seismic energy from the impact of an asteroid formed the heat of the heat. This hypothesis received an indirect confirmation when it was soon on the moon, sites with a similar relief were discovered, located diametically opposite to the sea of \u200b\u200brains and the sea oriental - two largest ring formations of the moon.
The structural figure of the crust of Mercury is determined to a large extent, as in the moon, large shock crater, around which the system of radial-concentric faults, dismembering the bark of Mercury to blocks. The largest crater has one, but two ring concentric shaft, which also resembles a lunar structure. At the captured half of the planet, 36 such crater was revealed.
Despite the overall similarity of Mercurian and lunar landscapes, completely unique were found on Mercury. geological structuresnot observed before any of the planetary bodies. They were called blade uniform ledgers, because for their outlines on the map, rounded protrusions are typical - "blades" by a diameter to several tens of kilometers. The height of the ledges from 0.5 to 3 km, in length, the largest of them reach 500 km. These ledgers are pretty cool, but unlike the lunar tectonic ledges, having a sharply pronounced slope slope, Mercurian blade uniforms have a smoothed surface of the surface inflection in their upper part.
These ledges are located in the ancient mainland areas of the planet. All of their features give reason to consider their surface expression of compression upper layers Planet bark.
Calculations of the compression value, made according to the measured parameters of all ledges on the filled half of Mercury, indicate a reduction in the area of \u200b\u200bthe cortex per 100 thousand km 2, which corresponds to a decrease in the radius of the planet for 1-2 km. This reduction could be caused by the cooled and hardening of the bowels of the planet, in particular its kernel continued and after the surface has already become solid.
Calculations showed that the iron core should have a mass of 0.6-0.7 masses of Mercury (for the Earth, the same value is 0.36). If all iron is concentrated in the Mercurian kernel, then its radius will be 3/4 of the planet radius. Thus, if the nucleus radius is approximately 1,800 km, it turns out that inside Mercury - a giant iron ball with a moon. The share of two external stone shells - mantle and bark - accounts for only about 800 km. That internal structure very similar to the structure of the Earth, although the size of Mercury shells is defined only in the most general features: even the thickness of the crust is unknown, it is assumed that it can be 50-100 km, then a layer of about 700 km remains on the mantle. On the ground, the mantle occupies the predominant part of the radius.
Relief details. The gigantic ledge of Discovery with a length of 350 km crosses two crater with a diameter of 35 and 55 km. Maximum height of the ledge of 3 km. It was formed when it comes to the upper layers of Mercury's bark from left to right. This happened due to the root of the cortex of the planet when compressing the metal kernel caused by its cooled. The ledger received the name of the ship James Cook.
The photo of the largest ring structure on Mercury is the heat plains surrounded by the mountains of the heat. The diameter of this structure is 1300 km. Only the eastern part of it is visible, and the central and western parts, not illuminated in this picture, have not yet been studied. Meridian district 180 ° z. D. - This is the most heated area of \u200b\u200bMercury, which is reflected in the names of the plain and mountains. Two main types of terrain on Mercury - ancient strongly moderated areas (dark yellow on the map) and younger smooth plains (brown on the map) - reflect the two main periods of the planet's geological history - the period of mass drop large meteorites And the period of the outpouring period of high-alone, alleged basalt lava followed by him.
Giant craters with a diameter of 130 and 200 km with an additional shaft at the bottom, a concentrant main ring shaft.
Santa Maria's winding ledger, named by the Krasip of Christopher Columbus, crosses ancient crater and later flat terrain.
The hilly-line terrain is a unique site of the surface of Mercury in its structure. There are almost no small craters here, but many clusters of low hills crossed by rectilinear tectonic faults.
Names on the map. The names of the Relief details of Mercury, revealed in the pictures of Mariner-10, were given by the International Astronomical Union. Craterics are assigned the names of world culture workers - famous writers, poets, artists, sculptors, composers. To designate plains (except for the plains of heat), the names of the Mercury Planet on different languages. Extended linear depressions - tectonic valleys - received the names of the radio operators who contributed to the study of the planets, and two ridges are large linear hills, were named after Astronomers Skiaparelie and Antoniadi, who made many visual observations. The most major blade uniform ledges received the names of marine ships, on which the most significant swimming in the history of mankind was performed.
Iron heart
The surprise was also the other data obtained by Mariner-10 and showed that Mercury has an extremely weak magnetic field, the value of which is only about 1% of the earth. This is insignificant at first glance the circumstance for scientists was extremely important because of all planetary bodies earth Group Global magnetosphere possess only land and Mercury. And the only most believable explanation of the nature of Mercurian magnetic field There may be a partially molten metal kernel in the depths of the planet, again the same earth. Apparently, Mercury has a very large core, which indicates the high density of the planet (5.4 g / cm 3), which makes it possible to assume that the mercury contains a lot of iron, the only widespread heavy element in nature.
To date, several possible explanations of the high density of Mercury with its relatively small diameter are put forward. According to the current theory of education, the planets believes that in the surchargeable dust cloud, the temperature adjacent to the Sun region was higher than in its outskirts, so light (so-called volatile) chemical elements endured in remote, colder parts of the cloud. As a result of this in the near-free region (where Mercury is now located), the predominance of heavier elements was created, the most common of which is iron.
Other explanations bind a high density of Mercury with chemical reduction of oxides (oxides) of light elements to their heavier, metallic, form under the action of very strong solar radiation, or with gradual evaporation and violating into space of the outer layer of the original planet's bark under the influence of solar heating, or With the fact that a significant part of the "stone" shell of Mercury was lost as a result of explosions and emissions of the substance in space When collishes with the celestial bodies of smaller sizes, such as asteroids.
The magnitude of the average density of Mercury is a mansion from all other planets of the earth group, including from the moon. Its average density (5.4 g / cm 3) is inferior only to the density of the Earth (5.5 g / cm 3), and if they bear in mind that the Earth density affects the stronger compression of the substance due to the larger size of our planet, then It turns out that with equal dimensions of the planets, the density of the Mercurian substance would be the greatest, exceeding the earth by 30%.
Hot Ice
Judging by the data available, the surface of Mercury, receiving great amount Solar energy is a real bake. Judge for yourself - the average temperature at the time of Mercurian half a day is about + 350 ° C. Moreover, when Mercury is at a minimum distance from the Sun, it rises to + 430 ° C, with the maximum removal, it is lowered to + 280 ° C. However, it is also established that immediately after sunset, the temperature in the one-digitatorial region is sharply reduced to -100 ° C, and it comes to -170 ° C to midnight, but after dawn, the surface is quickly heated to + 230 ° C. The measurement of the measurement in the radio view was shown that inside the soil at a small depth, the temperature does not depend on the time of day. What speaks of high thermal insulation properties of the surface layer, but since the light day lasts on Mercury 88 terrestrial days, then during which time it's good to warm up, even on a small depth, all sections of the surface have time.
It would seem that to talk about the possibility of existence in such conditions on Mercury Ice - at least absurd. But in 1992, during radar observations from the ground near the Northern and Southern Poles of the Planet, sections were first discovered, very strongly reflective radio waves. It was these data and were interpreted as evidence of ice presence in the near-surface Mercurian layer. The radar, made from the Arashibo Puerto Rico Rico Rico Rico-Rico-Rio Island, as well as from the NASA Cosmic Communications Center in Goldstone (California), was revealed about 20 rounded spots with a variation of several tens of kilometers having increased radio. Supposedly these crater, in which, because of their close location, the sun rays fall into the poles only casually or not fall at all. Such crater, called constantly shaded, are available on the moon, in them when measuring from satellites, the presence of a certain amount was revealed water ice. Calculations have shown that in the depressions of constantly shaded crater, Mercury Poles can be cold enough (-175 ° C) so that ice can exist there for a long time. Even at the plain areas near the poles, the calculated daytime temperature does not exceed -105 ° C. The immediate measurements of the temperature of the surface of the polar regions of the planet still do not have.
Despite the observations and calculations, the existence of ice on the surface of Mercury or at a small depth under it so far the unequivocal evidence has not received, since both stone rocks containing compounds of metals with sulfur and possible metal condensates, such as ions, possess increased radio input. Sodium, those who, as a result of a constant "bombardment" of Mercury, solar wind particles.
But then the question arises: why the distribution of areas that strongly reflect radio signals is clearly dedicated precisely to the polar regions of Mercury? Maybe the rest of the territory is protected from the solar wind by the magnetic field of the planet? Hope to clarify the mysteries about ice in the kingdom of heat are only connected with flight to the Mercury of new automatic space stationsequipped with measuring instruments allowing to determine chemical composition surface of the planet. Two such stations - "Messenger" and "Bun-Colombo" - are already preparing for flight.
Misleading Skiaparelli. Astronomers call Mercury difficult to observe the object, because on our sky it is removed from the sun no more than 28 ° and watch it is always low above the horizon, through the atmospheric haze on the background of the morning dawn (in the autumn) or in the evenings immediately after sunset (spring ). In the 1880s, the Italian astronomer Giovanni Skiaparelli on the basis of his observations Mercury concluded that this planet makes one turn around his axis exactly for the same time as one turnover in orbit around the sun, that is, "day" on it are equal year. Consequently, the same hemisphere is always drawn to the Sun, the surface of which is constantly redneled, and on the opposite side of the planet, the eternal darkness and cold reign. And since the authority of Skiaparelli as a scientist was great, and the conditions of observation of Mercury are difficult, almost a hundred years, this situation was not subject to doubt. And only in 1965 by radar observations with the help of the largest radio telescope "Arecibo" American scientists in Pettengill and R. Dais first determined reliably that Mercury makes one turn around the axis about 59 terrestrial days. This has become the largest discovery in the planetary astronomy of our time, which literally shocked the foundations of the ideas about Mercury. And after him followed another discovery - Professor of the Paduan University D. Colombo, noticed that the time of turnover of Mercury around the axis corresponds to 2/3 of his appeal time around the Sun. It was regarded as the presence of resonance between these two rotations, which originated due to the gravitational effects of the Sun on Mercury. In 1974, the American Automatic Station "Mariner-10", for the first time flew near the planet, confirmed that the day on Mercury lasts more than a year. Today, despite the development of cosmic and radar research of planets, Mercury observations by traditional methods of optical astronomy continue, albeit with the use of new tools and computer data processing methods. Recently in the Abastunum Astrophysical Observatory (Georgia) together with the Institute space studies The study of the photometric characteristics of the surface of Mercury, which gave new information about the microstructure of the top layer of the soil was performed.
In the vicinity of the sun. The nearest planet Mercury moves along a strongly elongated orbit, then approaching the luminaries at a distance of 46 million km, then removing from it by 70 million km. The strongly elongated orbit differs sharply from almost circular orbits of the rest of the planets of the earth group - Venus, Earth and Mars. The axis of rotation of Mercury is perpendicular to the plane of its orbit. One turnover in orbit around the Sun (Mercurian Year) lasts 88, and one turn around the axis is 58.65 terrestrial day. The planet rotates around his axis in the forward direction, that is, in the same, in which moves in orbit. As a result of the addition of these two movements, the duration of sunny day on Mercury is 176 terrestrial. Among the nine planets Solar system Mercury, whose diameter is 4,880 km, in the penultimate place in size, less than it is only Pluto. The force of gravity on Mercury is 0.4 from the earth, and the surface area (75 million km 2) is twice the lunar.
Murrecomers
The second start in the history of the automatic station sent to Mercury, "Messenger" - NASA plans to implement already in 2004. After launching, the station should twice (in 2004 and 2006) fly near Venus, the gravitational field of which will sparkle the trajectory so that the station is accurately reached by Mercury. Studies are scheduled to be held in two phases: first introductory - with a span trajectory at two meetings with the planet (in 2007 and 2008), and then (in 2009-2010) detailed - with orbits artificial satellite Mercury, the work on which will occur during one earth year.
When flying near Mercury in 2007, the eastern half of the uneasy hemisphere of the planet should be filmed, and a year later - Western. Thus, a global photo card of this planet will be obtained for the first time, and this would have been enough to consider this flight quite successful, however, the program of the "Messenger" work is much more extensive. During the two planned spans, the gravitational field of the planet will "slow down" the station so that with the next, third, meeting it would be able to switch to the orbit of the artificial satellite of Mercury with minimal removal from the planet 200 km and the maximum - 15 200 km. The orbit will be located at an angle of 80 ° to the equator of the planet. Low plot will be located above it northern hemispherethat will allow you to study in detail both the largest heat plates on the planet and the estimated "cold traps" in the craters near North PoleIn which the sun does not fall and where ice is assumed.
During the operation of the station in orbit around the planet, it is planned to perform detailed filming of the entire surface in various ranges of the spectrum, including color image of the area, determining the chemical and mineralogical compositions of the surface rocks, measuring the content of volatile elements in the near-surface layer for searching for ice concentration places.
In the next 6 months, very detailed studies of individual objects of the terrain, the most important for understanding the history of the geological development of the planet will be performed. Such objects will be selected according to the results of global shooting performed at the first stage. Also, the laser altimeter will be measured by the heights of the surface parts to obtain survey topographic maps. The magnetometer, located in the distance from the station on the sixth of 3.6 m long (in order to avoid interference from the instruments), will determine the characteristics of the magnetic field of the planet and possible magnetic anomalies on Mercury itself.
To take the planet from the "Messenger" and start the study of Mercury with the help of three stations at once, a joint project of the European Space Agency (ESA) and the Japanese Agency Aerospace Research (JAXA) - Bunikolombo are called up. Here, survey works are planned to be conducted using both two artificial satellites, as well as the landing apparatus. In the planned flight of the plane of the orbits of both satellites will be held through the planet's poles, which will allow observations to the entire surface of Mercury.
The main satellite in the form of a low prism weighing 360 kg will move along a weak orbit, then approaching the planet to 400 km, then removing from it by 1,500 km. A whole range of devices will be placed on this satellite: 2 cameras for overview and detailed surface shooting, 4 spectrometers for studying chi-bands (infrared, ultraviolet, gamma, x-ray), as well as a neutron spectrometer designed to detect water and ice. In addition, the main satellite will be equipped with a laser altimeter, with which a map of the surface heights of the entire planet must be prepared for the first time, as well as a telescope - to search for potentially dangerous for the collision of asteroids, which enter the internal areas of the solar system, crossing the earth orbit.
Overheating by the Sun, from which the Mercury comes 11 times more heat than to the ground, can lead to the failure of electronics operating at room temperatureOne half of the Messenger station will be covered with a semi-cylindrical heat insulating screen from a special ceramic fabric Nextel.
Auxiliary satellite in the form of a flat cylinder weighing 165 kg, called magnetospheric, is planned to be removed on a strongly elongated orbit with a minimum distance from Mercury 400 km and a maximum - 12,000 km. Working in a pair with the main satellite, it will measure the parameters of remote regions of the magnetic field of the planet, while the main will occur with the observation of the magnetosphere near Mercury. Such joint measurements will allow to construct a volumetric picture of the magnetosphere and its changes in time when interacting with the flow of charged particles of solar wind changing their intensity. On the auxiliary satellite there will also be installed a camera for shooting the surface of Mercury. The magnetospheric satellite is created in Japan, and the main is developed by scientists of European countries.
In the design of the landing apparatus, the GN Research Center is participating Babakina with NGO named S.A. Lavochkina, as well as the firms of Germany and France. Running "Bunicolombo" is planned to produce in 2009-2010. In this regard, two options are considered: either a single launch of all three devices of the Rocket "Arian-5" from the Kuru cosmodrome in French Guiana (South America), either - two separate starts from the Baikonur cosmodrome in Kazakhstan by Russian Soyuz-Frigate missiles (on the same-main satellite, on the other - the landing equipment magnetospheric satellite). It is assumed that the flight to Mercury will last 2-3 years, for which the device must fly relatively close to the moon and Venus, the gravitational effect of which "adjusts" its trajectory, giving the direction and the speed necessary to achieve the nearest surroundings of Mercury in 2012.
As already mentioned, research from satellites is planned to be held within one earth year. As for the landing unit, he will be able to work very short time - a strong heating to which it should be subjected to the surface of the planet will inevitably lead to the failure of its radio-electronic devices. During the interplanetary flight, a small dos-shaped landing apparatus (diameter 90 cm, a mass of 44 kg) will be "on the back" from the magnetospheric satellite. After their separation near Mercury, the landing apparatus will be launched into the orbit of an artificial satellite with a height of 10 km above the surface of the planet.
Another maneuver will translate it on the trajectory of decline. When 120 m remain to the surface of Mercury, the velocity of the landing unit should decrease to zero. At this point, he will begin a free fall on the planet, during which the plastic bags are filling with compressed air - they will force the device from all sides and soften his blow to the surface of Mercury, which it will touch at a speed of 30 m / s (108 km / h).
To reduce the negative impact of solar heat and radiation, the landing on Mercury is planned to produce in the polar region on the night side, not far from the line of the section of the dark and illuminated parts of the planet, with such a calculation, so that after 7 terrestrial days, the device "saw" the dawn and rising above the horizon The sun. In order for the onboard cameras able to get image of the area, it is planned to provide a landing block of a kind of spotlight. With the help of two spectrometers, which chemical elements and minerals are detected at the landing point. A small probe, called "Mole", will penetrate deep into the measurements of the mechanical and thermal characteristics of the soil. Seismometer will try to register possible "mercurestrynia", which, by the way, is very likely.
It is also planned that a miniature planet carrier comes from the landing apparatus to the surface - to study the properties of the soil at the adjacent territory. Despite the gradation of plans, the detailed study of Mercury is just beginning. And the fact that the earthlings intend to spend many strength and money for this, it is not by chance. Mercury is the only heavenly body, the inner structure of which is so similar to earthly, so for comparative planetology, it is an exceptional interest. Perhaps the study of this distant planet will shed light on the riddles, molding in the biographies of our Earth.
The "Ponolovbo" mission above the surface of Mercury: in the foreground - the main orbital satellite, in the distance - the magnetosphere module.
Lone guest."Mariner-10" is the only spacecraft investigating Mercury. The information obtained by it 30 years ago, still remain the best source of information about this planet. Flight "Mariner-10" is considered extremely successful - instead of the planned one once, he conducted a study of the planet three times. In the information obtained by him during the flight, all modern maps Mercury and the overwhelming majority of data on its physical characteristics. Reporting Mercury, all possible infractions, Mariner-10 has exhausted the resource of "livelihoods", but still continues to move silently on the previous trajectory, meeting with Mercury every 176 terrestrial days - exactly two turns of the planet around the Sun and through three turns of her around your axis. Because of this synchronicity of the movement, it always flies over the same area of \u200b\u200bthe planet, illuminated by the sun, just under the same angle, as in the first of its first span.
Solar dancing. The most impressive spectacle in Mercurian sky is the sun. There it looks 2-3 times big than on the earthly sky. Features of the combination of the speeds of rotation of the planet around their axis and around the Sun, and the same strong stretch of its orbits lead to the fact that the visible movement of the Sun on the Black Mercurian sky is not at all on Earth. At the same time, the path of the Sun looks unequal on different longtimes of the planet. So, in the areas of meridians 0 and 180 ° C. eightly in the morning in the eastern part of the sky over the horizon an imaginary observer could see "small" (but 2 times more than in the sky of the Earth), very quickly rising above the horizon shone, whose speed as it approaches the zenith gradually slows down, and itself It becomes brighter and hotter, increasing in size 1.5 times - this is Mercury, suitable on its strongly elongated orbit closer to the sun. I barely passing the point of Zenith, the sun freezes, it fows out a little back for 2-3 terrestrial days, it stops once again, and then begins to go down with ever-increasing speed and significantly decreasing in size - this Mercury is distinguished from the Sun, going into the elongated part of its orbits - And at high speed hiding behind the horizon in the West.
The daily course of the Sun near 90 and 270 ° z is quite different. D. The luminaire here discharges very amazing pyruetes - a day is three sunrise and three sunset. In the morning, because of the horizon in the East, a bright glowing case of a huge size appears very slowly (3 times more than on earthly sky), it rises a little over the horizon, stops, and then goes down and liftingly hidden behind the horizon.
Soon the re-sunrise follows, after which the sun begins to slowly crawl across the sky, gradually speeding up its turn and at the same time quickly decreasing in size and tile. The zenith point is the "small" sun flies at high speed, and then slows down its running, grows in size and slowly hidden behind the evening horizon. Shortly after the first sunset, the sun rises again to a small height, briefly freezes on the spot, and then falls back to the horizon and it becomes finally.
Such "zigzags" of the solar move occur because on the short segment of the orbit when passing the perihelion (minimum distance from the sun), the angular velocity of Mercury in orbit around the Sun becomes greater than the angular velocity of its rotation around the axis, which leads to the movement of the sun on the sky of the planet For a short period of time (about two terrestrial days), reversed its usual move. But the stars in the sky of Mercury move three times faster than the sun. The star, which appeared simultaneously with the Sun over the morning horizon, will go in the west before noon, that is, before the Sun gets to Zenith, and will have time to take another time in the east until the sun has been held.
Heaven over Mercury black and afternoon, and at night, and all because there is practically no atmosphere. Mercury is surrounded by only the so-called eczosphere - the space is so rarefied that the components of its neutral atoms never encounter. In it, according to the observations in the telescope from the Earth, as well as in the process of the spans near the planet Mariner-10 station, helium atoms were found (they prevail), hydrogen, oxygen, neon, sodium and potassium. The components of the exosphere atoms are "knocked out" from the surface of Mercury photons and ions, particles flying from the Sun, as well as micrometeorites. The absence of the atmosphere leads to the fact that there are no sounds on Mercury, since there is no elastic medium - air transmitting sound waves.
Georgy Burba, Candidate of Geographical Sciences
Time on Earth is perceived as something due. People do not think that the interval that the time is measured is relative. For example, the measurement of days and years occurs physical factors: The distance from the planet to the Sun is taken into account. One year equal to that The time for which the planet goes around the Sun, and one day is the time of full turn around its axis. On this principle, time is calculated on other heavenly bodies Solar system. Many people are interested, and how much is a day for Mars, Venus and other planets?
On our planet, the day lasts 24 hours. It is for so much hours that the earth performs a turn around its axis. The length of the day on Mars and other planets is different: somewhere he is short, and somewhere very long.
Determining the time
To find out how much a day for Mars, you can use solar or star day. The last measurement option is a period during which the planet makes one turn around its axis. The day doubt the time that the stars have become in the sky at the same position from which the countdown began. The star path of the Earth is 23 hours and almost 57 minutes.
Sunny day is a time unit for which the planet turns around the axis relatively sunlight. The principle of measuring this system is the same as when measuring the day of the star day, the sun is used as a reference point. Star and sunny day can be different.
And how much is a day for Mars on the star and solar system? Star day on the red planet are 24 and a half hours. Sunny day continues a little longer - 24 hours and 40 minutes. A day on Mars is 2.7% longer than the earth.
When sending devices for the study of Mars, the time is taken into account on it. In the devices there are special built-in hours, divergent with Earth by 2.7%. Knowledge of how much a day for Mars lasts, allow scientists to create special rinsing, which are synchronized with Martian days. The use of special hours is important for science, as the rinsing works on solar panels. As an experiment, the clocks that take into account the sunny day were developed for Mars, but they could not be applied.
The zero meridian on Mars consider the one that passes through the crater called Eyry. However, there are no time zones on the red planet as on Earth.
Martian time
Knowing how many hours in the days on Mars, you can calculate, what is the duration of the year. The seasonal cycle is similar to Earth: Mars has the same inclination as the land (25.19 °) with respect to its own orbital plane. From the Sun to the Red Planet, the distance ranges at different periods from 206 to 249 million kilometers.
Temperatures differ from ours:
- the average temperature is -46 ° C;
- during the removal period, the temperature is about -143 ° C;
- in summer time - -35 ° C.
Water on Mars
An interesting discovery made scientists in 2008. The rover discovered on the poles of the planet water ice. Prior to this discovery it was believed that there are only carbon dioxide on the surface. Even later it turned out that precipitation in the form of snow falls on the red planet, and near southern Pole. drops carbon dioxide.
Throughout the year, storms extending hundreds of thousands of kilometers are observed on Mars. They interfere with tracking what is happening on the surface.
Year on Mars
Around the Sun, the Red Planet makes a circle for 686 terrestrial days, moving at a speed of 24 thousand kilometers per second. A whole system of designating Martian years has been developed.
When studying the question of how much a day last on Mars in the clock, humanity made many sensational discoveries. They show that the red planet is close to the ground.
Duration of the year on Mercury
Mercury is close to the planet sun. She makes a turn around his axis for 58 terrestrial days, those there are one day at Mercury make up 58 terrestrial day. And in order to fly around the sun, the planet requires only 88 terrestrial days. This amazing discovery shows that there are almost three terrestrial months on this planet, and while our planet flies out one circle around the sun, Mercury performs more than four revolutions. And how much is a day for Mars and other planets when compared with Mercurian time? It is amazing, but in just one and a half of the Martian day at Mercury passes a whole year.
Time on Venus
Unusual is the time on Venus. One day on this planet lasts 243 terrestrial days, and the year on this planet lasts 224 terrestrial days. It seems strange, but such a mysterious Venus.
Time for Jupiter
Jupiter - Sameya big planet Our solar system. Based on its size, many believe that the day on it lasts long, but it is not. Its duration is 9 hours 55 minutes - it is less than half the duration of our Earth Day. Gaza giant Quickly rotates around its axis. By the way, because of him on the planet, constant hurricanes are raging, strong storms.
Time at Saturn
The day on Saturn lasts about as much as in Jupiter, and is 10 hours 33 minutes. But the year lasts about 29345 terrestrial years.
Time in uranium
Uranus is an unusual planet, and determine how much the light day will last on it, not so simple. Star day on the planet lasts 17 hours and 14 minutes. However, the giant has a strong tilt axis, which is why he rotates around the sun almost on the side. Because of this, in one pole, the summer will last 42 terrestrial years, while on the other pole at this time will be night. When turning the planet, another pole will be covered with 42 years. Scientists came to the conclusion that the day on the planet lasts 84 Earth years: one Uranan year lasts almost one uranium day.
Time on other planets
Looking for a question about how much a day and a year on Mars and other planets, scientists found unique exoplanets, where the year lasts only 8.5 terrestrial hours. This planet is called KEPLER 78B. Another Planet KOI 1843.03 was also discovered, with a shorter period of rotation around his sun - only 4.25 terrestrial hours. Every day, a man would have become three years older if he would not live on earth, but on one of these planets. If people could adapt to the planetary year, then it is best to go to Pluto. On this dwarf year is 248.59 Earth years.
Quoted1 \u003e\u003e Day on Mercury
- The first planet of the solar system. Description of the influence of orbits, rotation and distance from the sun, Mercury Day with the photo of the planet.
Mercury - Example of the planet of the solar system, which adores to fall in extremes. This is the closest planet to our star, which is forced to experience strong temperature fluctuations. And so far the illuminated side suffers from the decrease, dark frozen to critical marks. Therefore, there is nothing surprising that Mercury's Day does not fit into standards.
How long does day last on Mercury
The situation with the daytime cycle of Mercury does seem strange. Year covers 88 days, but slow rotation increases the day twice! If you were on the surface, we would have followed the sunrise / sunset of a whole 176 days!
Distance and orbital period
This is not only the first planet from the sun, but also the owner of the most eccentric orbit. If the average distance extends 57909050 km, then in the perihelion it is approaching 46 million km, and in Aflia, drives up 70 million km.
Due to the proximity of the planet has the most rapid orbital period, changing depending on the position in orbit. Faster all shifts with a short distance, and slows down at remoteness. Middle high-speed orbital indicator - 47322 km / s.
The researchers thought that Mercury repeats the situation of the earthly moon and always turn to the sun with one side. But the measurements of the radar in 1965 were made to understand that the axial rotation was much slower.
Sideric and sunny days
Now we know that the resonance of axial and orbital rotation is 3: 2. That is, there are 3 turns on 2 orbits. At a speed mark at 10.892 km / h per turn around the axis takes 58.646 days.
But let's be more accurate. Rapid orbital speed and slow cider rotation do so that day on Mercury lasts 176 days. Then the ratio of 1: 2. Only the polar regions do not fit into this rule. For example, the crater on the northern polar cap always dwells in the shade. There is a low temperature mark, therefore allows you to secure ice reserves.
In November 2012, assumptions were confirmed when Messenger applied the spectrometer and considered ice and organic molecules.
Yes, add the fact that the day on Mercury covers as many as 2 years.
The science
Imagine that every day you become older for 3 years. If you lived on one exoplanet, you would feel it on yourself. Scientists have discovered a planet, the size of the ground, which revolves around his star just 8.5 hours.
Exoplanet, named Kepler 78B, is at a distance of 700 light years from the ground, and she has one of the shortest periods of orbit.
Since it is very close to his star, its surface temperature reaches 3000 degrees on Kelvin or 2726 degrees Celsius.
With such a medium, the surface of the planet is most likely completely melted, and is the huge stormy ocean is very hot lava.
Exoplates 2013.
Detect the planet was not easy. Before you find a supergious exoplanet, scientists explored more than 150,000 stars, followed by the Kepler telescope. Now researchers browse the telescope data in the hope find a planet size with an earth that was potentially inhabited.
Scientists caught light reflected or emanating from the planet. They determined that Kepler 78B is 40 times closer to his starthan Mercury to our sun.
In addition, the parent star is relatively young, as it rotates twice as fast as the sun. This suggests that there is not so much time to have time to slow down.
In addition, scientists have discovered planet KOI 1843.03 with an even shorter appeal period, where the year lasts only 4.25 hours.
It is so close to his star, which almost completely consists of iron, since something else would simply be destroyed by incredible tidal forces.
Planets of the Solar System: How long does it last a year?
The land is in constant movement: it revolves around his axis (day) and makes turn around the sun (year).
The year on Earth is the time required by our planet to make a turn around the sun, makes up a little more than 365 days.
However, other planets of the solar system turn around the Sun at different speeds.
How long does the year on the planets of the solar system?
Mercury - 88 days
Venus - 224.7 days
Earth - 365, 26 days
Mars - 1.88 Earth years
Jupiter - 11.86 Earth years
Saturn - 29.46 Earth years
Uranium - 84 Earth years
Neptune - 164.79 Earth years
Pluto ( dwarf Planet.) - 248, 59 Earth years
0.147 Earth
0,056 Earth
0.055 Earth
0,984 Earth
0,38
281.01 °
0.106 (Geom. Albedo)
24.9% sodium
9.5%, A. Oxygen
7.0% Argon
5.9% helium
5.6%, M. Oxygen
5.2% nitrogen
3.6% carbon dioxide
3.4% water
3.2% hydrogen
Mercury in natural color (MARINER 10 shot)
Mercury - The closet to the sun planet of the solar system, draws around the Sun for 88 terrestrial day. Mercury refers to the inner planets, as its orbit goes closer to the Sun than the main belt of asteroids. After the deprivation of Pluto in 2006, the status of Planet Mercury passed the title of the smallest planet of the solar system. The visible star magnitude of Mercury ranges from -2.0 to 5.5, but it is not easy to see it because of the very small angular distance from the Sun (maximum 28.3 °). In high latitudes, the planet can never be seen on the dark night sky: Mercury is always hiding in the morning or evening dawn. The optimal time for observing the planet is the morning or evening twilight during the periods of its elongations (periods of maximum removal of Mercury from the Sun in the sky coming several times a year).
Observe Mercury is convenient in low latitudes and near the equator: This is due to the fact that the duration of twilight is the smallest. In medium latitudes to find Mercury much more difficult and only during the best elongations, and in high latitudes it is impossible at all.
The planet is still known to be relatively few. The Mariner-10 apparatus, who studied Mercury in -1975, managed to map only 40-45% of the surface. In January 2008, Messenger interplanetary station flew past Messenger, which will enter orbit around the planet in 2011.
In its physical characteristics, Mercury resembles the moon, is highly moderated. There is no planet natural satellitesBut there is a very rarefied atmosphere. The planet has a large iron core, which is the source of the magnetic field along its totality of 0.1 from the earth. Mercury's core is 70 percent of the total volume of the planet. The temperature on the surface of Mercury varies from 90 to 700 (from -180 to +430 ° C). Solar side heats up much more than polar areas and back side planets.
Despite the smaller radius, Mercury still exceeds the mass of such satellites of planets-giants as Gamornad and Titan.
The astronomical symbol of Mercury is a stylized image of the winged helmet of the God of Mercury with his cadouch.
History and title
The most ancient testimonies of Observation of Mercury can be found in the Sumerian clinox texts dating back to the third millennium BC. e. Planet is named after the god of Roman Pantheon Mercury, Greek analogue Hermesa and Babylonian Nabu. The ancient Greeks of the times of the geyode called the Mercury "στίλβων" (stylbon, brilliant). Until the V century BC e. Greeks believed that Mercury, visible at the evening and morning sky - two different objects. In ancient India, Mercury called Buddha (बुध) and Roginea. In Chinese, Japanese, Vietnamese and Korean languages, Mercury is called Water Star (水星) (in accordance with the views on the "five elements". In Hebrew, the name of Mercury sounds like "Kohav Hama" (כוכב חמה) ("Sunny Planet").
Planet movement
Mercury moves around the Sun along a fairly elongated elliptical orbit (Eccentricity 0.205) at an average distance of 57.91 million km (0.387 or. E.). In the perihelion, Mercury is 45.9 million km from the Sun (0.3 А.), in Aflia - 69.7 million km (0.46 А.) in the perihelion of Mercury more than one and a half times closer to the sun than in Aflia. The tilt of the orbit to the plane of the ecliptic is 7 °. For one turnover of orbit, Mercury spends 87.97 days. The average speed of the planet in orbit is 48 km / s.
For a long time it was believed that Mercury was constantly addressed to the Sun and the same side, and one turn around the axis occupies the same 87.97 days. Observations of parts on the surface of Mercury, made at the limit of the resolution, seemed to be contrary to this. This error was due to the fact that the most favorable conditions for observation of Mercury are repeated through a triple synodic period, that is, 348 terrestrial days, which is approximately equal to the six-time period of rotation of Mercury (352 days), so at various times there was approximately the same section of the surface. Planets. On the other hand, some astronomers believed that the Mercurian day is approximately equal to the earth. The truth was revealed only in the mid-1960s, when Mercury radar was carried out.
It turned out that Mercurian star days are equal to 58.65 terrestrial days, that is, 2/3 of Mercurya. Such a commensity of the periods of rotation and circulation of Mercury is unique to the solar system. It is allegedly explained by the fact that the tidal effect of the Sun selected the moment of the amount of movement and slowed down the rotation, which was originally faster, until both periods were linked by an integer attitude. As a result, for one Mercurian year, Mercury has time to turn around its axis on a half turn. That is, if at the time of passing the pericuria perihelium, a certain point of its surface is facing exactly to the Sun, then the opposite point of the surface will be drawn to the Sun, and after another Mercurian year, the sun will return to the zenith over the first point again. As a result, the sunny day on Mercury lasts two Mercurian years or three Mercurian star days.
As a result of such a movement of the planet, it can be distinguished by "hot longitude" - two opposite meridian, which alternately addressed to the Sun during the passage of the perigel meringue, and on which, because of this, it is especially hot and even in Mercurian standards.
The combination of the planet's movements generates another unique phenomenon. The speed of rotation of the planet around the axis is the value almost constant, while the rate of orbital movement is constantly changing. On the orbit area near the perigelium for about 8 days the rate of orbital motion exceeds the speed of rotational motion. As a result, the sun in the sky of Mercury stops, and begins to move in the opposite direction - from the west to the east. This effect is sometimes referred to as the effect of Joshua, named the main character of the Book of Joshua from the Bible, who stopped the movement of the Sun (Nav., X, 12-13). For an observer on the longitents, stretching 90 ° from "hot longitude", the sun rises (or comes) twice.
It is also interesting that, although Mars and Venus are closest to Earth closest, it is Mercury that is most of the time the planet closest to Earth than any other (since others are to a greater extent, not being so "attached" to the Sun).
physical characteristics
Comparative dimensions of Mercury, Venus, Earth and Mars
Mercury is the smallest planet of the earth group. Its radius is only 2439.7 ± 1.0 km, which is less than the radius of the satellite of Jupiter of Ganamed and Satutnik Titan. The mass of the planet is 3.3 × 10 23 kg. The average density of Mercury is quite large - 5.43 g / cm³, which is only slightly less than the density of the Earth. Given that the land is larger in size, the mercury density value indicates an increased content in its depths of metals. Acceleration of free fall on Mercury is 3.70 m / s². Second cosmic speed - 4.3 km / s.
Crater Koyper (just below the center). Snapshot Messenger
One of the most notable details of the surface of Mercury is the heat plain (lat. Caloris Planitia.). This crater got its name, because it is located near one of the hot longitude. Its diameter is about 1,300 km. Probably the body when the crater was formed when the crater was formed, there was a diameter of at least 100 km. The blow was so strong that seismic waves, having passed the entire planet and focused on the opposite point of the surface, led to the formation of a peculiar crossed "chaotic" landscape.
Atmosphere and physical fields
When the spacecraft "Mariner-10" passes by Mercury, the presence of an extremely rarefied atmosphere in the planet, the pressure of which is 5 × 10 11 times less than the pressure of the earth's atmosphere. In such conditions, atoms are more often encountered with the surface of the planet than each other. Its atoms captured from the solar wind or sandwiched with solar wind from the surface - helium, sodium, oxygen, potassium, argon, hydrogen. The average lifetime of a certain atmosphere in the atmosphere is about 200 days.
Mercury has a magnetic field, the tension of which is 300 times less than the voltage of the magnetic field of the Earth. Mercury magnetic field has a dipole structure and high degree Symmetrically, and its axis is only 2 degrees from the axis of rotation of the planet, which imposes a significant limitation on the circle of theories explaining its origin.
Research
Picture of the surface of the Mercury surface obtained by Messenger apparatus
Mercury - the least studied planet of the earth group. Only two devices were sent for its research. The first was "Marinener-10", which in -1975 flew three times past Mercury; The maximum rapprochement was 320 km. As a result, several thousand pictures were obtained covering approximately 45% of the surface of the planet. Further studies from the Earth showed the possibility of water ice in polar craters.
Mercury in art
- In the scientific fiction story Boris Lyapunov "Nearest to the Sun" (1956) soviet cosmonauts For the first time landed on Mercury and Venus to study them.
- In the story of Isalet Azimov "Big Sun of Mercury" (series about Lakki Starre) The action takes place on Mercury.
- In the stories of Isima Azimov "Horovod" (Runaround) and "Night that dies" (The Dying Night), written, respectively, in 1941 and 1956, describes Mercury, turned to the Sun to one side. At the same time, in the second story, the detective plot is built on this fact.
- In the science fiction novel Francis Karsaka "Fiashide of the Earth", along with the main plot, describes a scientific station for studying the Sun, located on the North Pole of Mercury. Scientists live on the basis located in the eternal shadow of deep craters, and observations are conducted with constantly illuminated by the luminaries of giant towers.
- In the scientific fiction story of Alan Nurts "through the sunny side", the main characters crosses the side of Mercury facing the sun. The story is written in accordance with the scientific views of his time when it was assumed that Mercury is constantly addressed to the Sun one side.
- In the anime-cartoon series "Sailor Moon" the planet personifies the Warrior girl Sailor Mercury, she is Mitsuno. Her attack is the power of water and ice.
- In the scientific fiction story of Clifford, Saimaka "Once upon a time on Mercury", the main field of action is Mercury, and the energy form of life on it - balls, exceeds humanity to millions of years of development, which has long passed the stage of civilization.
Notes
see also
Literature
- Bronshtan V. Mercury is the closest to the Sun // Aksenova M. D. Encyclopedia for children. T. 8. Astronomy - M.: Avanta +, 1997. - P. 512-515. - ISBN 5-89501-008-3.
- Xanfomaliti L. V. Unknown Mercury // In the world of science. - 2008. - № 2.
Links
- Website about Messenger Mission (English)
- Photos of Mercury made by messenger (eng.)
- Section on the Bepicolombo Mission (English) on Jaxa
- A. Levin. Iron Planet Popular Mechanics № 7, 2008
- "The closest" Lenta.ru, October 5, 2009, photos of Mercury made by the "Messenger"
- "Published new pictures of Mercury" Lenta.ru, November 4, 2009, about rapprochement on the night from 29 to September 30, 2009, Messenger and Mercury
- "Mercury: Facts & Figures" NASA. Gym physical characteristics planets.
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