An artificial satellite of Mercury. Planets and their satellites Moons of the planet mercury names
The solar system was formed about 4.6 billion years ago. A group of planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, together with the Sun make up the Solar System.
Sun
The sun is the central body solar system is a star, a huge ball of gas, in the center of which nuclear reactions take place. The bulk of the mass of the solar system is concentrated in the Sun - 99.8%. That is why the Sun holds by gravity all the objects of the solar system, the size of which is not less than sixty billion kilometers Samygin S.I. Concepts of modern natural science - Rostov-on-Don, Phoenix, 2008.
Very close to the Sun, four small planets circulate, consisting mainly of rocks and metals - Mercury, Venus, Earth and Mars. These planets are called terrestrial planets.
Between the terrestrial planets and the giant planets is the asteroid belt Sagan K.E. Space - M., 2000 .. A little further there are four large planets, consisting mainly of hydrogen and helium. The giant planets do not have a solid surface, but they have an exceptionally powerful atmosphere. Jupiter is the largest of them. Followed by Saturn, Uranus and Neptune. All giant planets have a large number of satellites, as well as rings.
The very last planet in the solar system is Pluto, which physical properties closer to the satellites of the giant planets. Beyond the orbit of Pluto, the so-called Kuiper belt, the second asteroid belt, has been discovered.
Mercury, the closest planet to the Sun in the solar system, was for astronomers long time a complete mystery. The period of its rotation around the axis was not accurately measured. Due to the lack of satellites, the mass was not known exactly. Proximity to the Sun prevented observations of the surface.
Mercury
Mercury is one of the brightest objects in the sky. In brightness, it is second only to the Sun, Moon, Venus, Mars, Jupiter and the star Sirius. In accordance with Kepler's 3rd law, it has the shortest period of revolution around the Sun (88 Earth days). And the highest average orbital speed (48 km / s) Hoffman V.R. Concepts of modern natural science - M., 2003 ..
The mass of Mercury is equal to the mass of the Earth. The only planet with less mass is Pluto. In terms of diameter (4880 km, less than half of the earth), Mercury also stands in the penultimate place. But its density (5.5 g/cm3) is approximately equal to the density of the Earth. However, being much smaller than the Earth, Mercury experienced a slight compression under the influence of internal forces. Thus, according to calculations, the density of the planet before compression is 5.3 g/cm3 (for the Earth, this value is 4.5 g/cm3). Such a large uncompressed density, surpassing the density of any other planet or satellite, indicates that internal structure the planet is different from the structure of the Earth or the Moon Isaac A. Earth and space. From reality to hypothesis - M., 1999 ..
The large value of the uncompressed density of Mercury must be due to the presence of a large amount of metals. According to the most plausible theory, in the bowels of the planet there should be a core consisting of iron and nickel, the mass of which should be approximately 60% of the total mass. And the rest of the planet should consist mainly of silicates. The core diameter is 3500 km. Thus, it lies at a distance of about 700 km from the surface. Simplistically, you can imagine Mercury as a metal ball the size of the Moon, covered with a rocky 700 km crust.
One of the unexpected discoveries made by the American space mission "Mariner 10" was the detection of a magnetic field. Although it is approximately 1% of the Earth, it is just as significant for the planet. This discovery was unexpected due to the fact that it was previously believed that inner part planets are in a solid state, and, therefore, a magnetic field could not form. It is difficult to understand how such a small planet could store enough heat to keep the core in a liquid state. The most likely assumption is that the core of the planet contains a significant part of the iron and sulfur compounds, which slow down the cooling of the planet and due to this, at least the iron-gray part of the core is in a liquid state Sagan K.E. Space - M., 2000 ..
The first data characterizing the planet from a close distance were obtained in March 1974 thanks to a spacecraft launched as part of the American space mission Mariner 10, which approached at a distance of 9500 km and photographed the surface at a resolution of 150 m.
Although the surface temperature of Mercury has already been determined on Earth, more accurate data have been obtained from close measurements. The temperature on the day side of the surface reaches 700 K, approximately the melting point of lead. However, after sunset, the temperature quickly drops to about 150 K, after which it cools more slowly to 100 K. Thus, the temperature difference on Mercury is about 600K, which is greater than on any other planet Sadokhin A.P. Concepts of modern natural science - M., Unity, 2006 ..
Mercury strongly resembles the Moon in appearance. It is covered with thousands of craters, the largest of which reach 1300 km in diameter. Also on the surface there are steep slopes that can exceed a kilometer in height and hundreds of kilometers in length, ridges and valleys. Some of the largest craters have rays like the craters Tycho and Copernicus on the Moon, and many of them have central peaks. Gorkov VL, Avdeev Yu.F. Space alphabet. Book about space - M., 1984 ..
Most of the relief objects on the surface of the planet were named after famous artists, composers and representatives of other professions who contributed to the development of culture. The largest craters are named Bach, Shakespeare, Tolstoy, Mozart, Goethe.
In 1992, astronomers discovered areas with high level reflections of radio waves, similar in their properties to the properties of reflection at the poles on Earth and Mars. It turned out that these areas contain ice in craters covered with shadow. Although the existence of such low temperatures was not unexpected, the mystery was the origin of this ice on the planet, the rest of which is exposed to high temperatures and is completely dry.
Distinctive features of Mercury - long escarpments, which sometimes cross craters, are evidence of compression. Obviously, the planet was shrinking, and cracks were going along the surface. And this process took place after most of the craters formed. If the standard crater chronology is correct for Mercury, then this shrinkage must have occurred during the first 500 million years of Mercury's history.
The planet Mercury is the smallest planet of the terrestrial group, the first from the Sun, the innermost and smallest planet in the solar system, revolving around the Sun in 88 days. The apparent magnitude of Mercury ranges from -2.0 to 5.5, but is not easy to see due to its very small angular distance from the Sun. Its radius is only 2439.7 ± 1.0 km, which is less than the radius of the moon Ganymede and the moon Titan. The mass of the planet is 3.3x1023 kg. The average density of the planet Mercury is quite high - 5.43 g / cm³, which is only slightly less than the density of the Earth. Considering that the Earth is larger in size, the value of the density of Mercury indicates an increased content of metals in its bowels. The free fall acceleration on Mercury is 3.70 m/s². The second space velocity is 4.3 km/s. The planet can never be seen in the dark night sky. The optimal time for observing the planet is the morning or evening periods of the maximum distance of Mercury from the Sun in the sky, which occur several times a year. Relatively little is known about the planet. In 1974-1975, only 40-45% of the surface was photographed. In January 2008, the MESSENGER interplanetary station flew past Mercury, which will enter orbit around the planet in 2011.
In its physical characteristics, Mercury resembles the Moon. It is dotted with many craters, the largest of which is named after the great German composer Beethoven, its diameter is 625 km. The planet has no natural satellites, but has a very rarefied atmosphere. The planet has a large iron core, which is the source of the magnetic field and, in its totality, is 0.1 of the earth's. Mercury's core makes up 70% of the planet's total volume. The temperature on the surface of Mercury ranges from 90 to 700 K (-180, 430 °C). Despite the smaller radius, the planet Mercury still surpasses in mass such satellites of the giant planets as Ganymede and Titan. Mercury moves around in a rather highly elongated elliptical orbit at an average distance of 57.91 million km. The inclination of the orbit to the plane of the ecliptic is 7 degrees. Mercury spends 87.97 days per orbit. The average speed of the planet in orbit is 48 km/s. In 2007, Jean-Luc Margot's team summarized five years of radar observations of Mercury, during which they noticed variations in the planet's rotation that were too large for a model with a solid core.
The proximity to the Sun and the rather slow rotation of the planet, as well as the absence of an atmosphere, lead to the fact that Mercury experiences the sharpest temperature drops in. average temperature its daytime surface is 623 K, the nighttime surface is only 103 K. Minimum temperature on Mercury it is 90 K, and the maximum reached at noon at "hot longitudes" is 700 K. Despite these conditions, there have recently been suggestions that ice may exist on the surface of Mercury. Radar studies of the polar regions of the planet have shown the presence of a highly reflective substance there, the most likely candidate for which is ordinary water ice. Entering the surface of Mercury when comets hit it, water evaporates and travels around the planet until it freezes in the polar regions at the bottom of deep craters, where the Sun never looks, and where ice can remain almost indefinitely.
On the surface of the planet, smooth rounded plains were discovered, which received the name of basins by their resemblance to the lunar "seas". The largest of them, Kaloris, has a diameter of 1300 km (the ocean of Storms on the Moon is 1800 km). The appearance of valleys is explained by intense volcanic activity, which coincided in time with the formation of the planet's surface. The planet Mercury is partially strewn with mountains, the height of the highest reaches 2–4 km. In some regions of the planet, valleys and craterless plains are visible on the surface. On Mercury, there is also an unusual detail of the relief - the scarp. This is a 2–3 km high protrusion separating two surface areas. It is believed that the scarps formed as shifts during the early compression of the planet.
The oldest evidence of the observation of the planet Mercury can be found in Sumerian cuneiform texts dating back to the third millennium BC. The planet is named after the god of the Roman pantheon Mercury, an analogue of the Greek Hermes and the Babylonian Naboo. The ancient Greeks of the time of Hesiod called Mercury. Until the 5th century BC the Greeks believed that Mercury, visible in the evening and morning sky, are two different objects. IN ancient india Mercury was called Buddha and Roginea. In Chinese, Japanese, Vietnamese and Korean, Mercury is called the Water Star (in accordance with the ideas of the "Five Elements". In Hebrew, the name of Mercury sounds like "Koha in Hama" ("Solar Planet").
A celestial body that revolves around the orbit of another object in outer space is called a satellite. In the solar system, almost every planet has it. Some planets have dozens of them. For example, the gas giant Jupiter has 67 moons. Pluto has five. But Mercury is completely alone, all the asteroids fly by. Why does the first planet from the Sun have no satellite?
Search history of alleged objects
The question of whether there are satellites was raised as early as 1970. The space station caught ultraviolet radiation next to him. The speed of the alleged object was 4 km/s. After lengthy research, it was found that 31 stars of the Chalice constellation were the source of radiation. Attempts by scientists to find lingering asteroids in the orbit of Mercury are in vain.
How do planets get moons?
The Earth found its satellite at the time of its formation. A large celestial body crashed into it. Shards due to gravity merged into one. This is how the moon was formed. Mercury could have met the same fate, but the meteorites could have left the gravitational field.
The two moons are asteroids covered by gravity. They were formed due to the fact that Mars is located near the asteroid belt.
Pluto literally "caught" its satellites when several asteroids flew by. Its moons are ice blocks that can disappear if they get too close to the scorching Sun.
Causes of absolute loneliness
Mercury has no natural moons because it rotates too slowly. One revolution around its axis takes 88 Earth days. Because of this, it has a wide synchronous orbit, which is 240 thousand km away. If the probable asteroids were below orbit, then they could succumb to the influence of the gravitosphere. Does Mercury have satellites above orbit? They are not and cannot be because of their proximity to the Sun. Its attraction absorbs all possible bodies in the mercurial space.
The first planet will not have natural celestial bodies. For their occurrence, the fall of a huge number of meteorites is necessary. They could bounce and “hook”, but due to the weak gravitational force, this is unlikely.
artificial satellites
The first Messenger spacecraft was launched in 2011. In space, it lasted until April 2015. Thanks to the stable operation of the instruments, it was possible to study the celestial body in more detail and take pictures of excellent resolution. Scientists determined the angle of inclination, the period of revolution, dimensions, and also studied the relief from a close distance.
The Messenger interplanetary probe was launched in early August 2004 from Cape Canaveral by American specialists. The name of the device from English is translated as "messenger". This name perfectly reflects the mission of the probe, which was to reach the remote planet Mercury and collect data of interest to scientists. The unique flight of the spacecraft riveted the attention of many researchers, anxiously awaiting the first results from Mercury.
The journey of the messenger of the Earth lasted almost seven years. During this time, the device flew more than 7 billion kilometers, as it had to perform a series of gravitational maneuvers, slipping between the fields of the Earth, Venus and Mercury itself. The voyage of the artificial vehicle turned out to be one of the most difficult missions in the history of space exploration.
In March 2011, several calculated approaches of the probe to Mercury took place, during which the Messenger corrected its orbit and included a fuel saving program. When the maneuvers were completed, the probe was actually an artificial satellite of Mercury, revolving around the planet in an optimal orbit. The messenger from Earth has begun the main part of his mission.
Artificial satellite of Mercury on a space watch
As an artificial satellite of Mercury, the Messenger probe worked until mid-March 2013, flying around the surface at an altitude of about 200 km. During its stay near the planet, the probe collected and transmitted to Earth a lot of useful information. Many of the data were so unusual that they changed the usual understanding of scientists about the features of Mercury.
Today it became known that in ancient times there were volcanoes on Mercury, and the geological composition of the planet is complex and diverse. Mercury's core is made up of molten metal. There is also a magnetic field, which, however, behaves rather strangely. It is still difficult for specialists to draw accurate conclusions about the presence of an atmosphere on the planet and its possible composition. This will require additional research.
An additional bonus to the collection of scientists was a unique "photo portrait" of the solar system, which was made by the first artificial satellite of Mercury. The photo shows almost all the planets in the solar system, with the exception of Uranus and Neptune. Having completed its scientific mission in 2013, the NASA probe has made an invaluable contribution to the development of ideas about space objects closest to the Earth.
Brown-gray Mercury is the little-studied first planet of our solar system. After object #9 Pluto was demoted from the title of "planet", the closest neighbor of the Sun became the smallest planet. Object No. 1 is endowed with many secrets and unsolved facts. Scientists are still worried about the question of whether there are satellites of Mercury in outer space.
artificial satellite
The jumping planet, as the ancient inhabitants of the Earth called Mercury, has been of interest to astronomers since the time dating back to the name “BC”. The ancient Egyptians and Romans have references to the mysterious "morning star", while the Sumerians, who saw Mercury in the sky, called it "Mul'apin".
After modern technology went forward by leaps and bounds, Mercury became one of the main objects of space exploration and our solar system. Looking at the planet through telescopes, astronomers have long cherished hopes to take a closer look at the first neighbor of the star and understand what is happening on it.
For the first time, it was possible to send a probe towards the brown-gray object No. 1 in 1973. The American research company NASA sent the Mariner-10 probe to conquer the near-Mercurian expanses. The task of the device was to fly over a small planet and photograph its surface. Since satellites were not previously seen near Mercury, scientists hoped that Mariner 10 would be able to identify objects possibly hidden in the shadow of the planet.
The hope that the planet still has a satellite or some object in orbit was given to astronomers by ultraviolet radiation, the activity of which was observed before the passage of the planet space boundary probe No. 1. Mariner 10, which arrived at the horizons of Mercury in March 1974, did not detect a mysterious stellar object that disturbed the terrestrial equipment of the flying probe, and the ultraviolet burst dissipated as if it had never existed.
Again, hope that Mercury's satellites still exist appeared a few days later, when the NASA probe again caught an ultraviolet burst and recorded an object moving away from the planet at a speed of 4 m per second. Further analysis of the data showed that Mariner 10 recorded information from a completely different distant object located in a neighboring galaxy.
The first artificial satellite of the planet No. 1 was destined to become a new NASA device. The modern conqueror of the starry expanses was called "Messenger". Having successfully launched on August 3, 2004 from Cape Canaveral, the “spy” of earthlings reached a brown-gray body in early 2008. The Messenger device transmitted the first images to the mission control center, and scientists once again realized that the natural satellites of Mercury does not exist.
In 2011, a terrestrial vehicle owned by an American aerospace company made several maneuvers in the object's weak atmosphere and forever became its first man-made companion to Mercury. But the list of artificial objects near planet No. 1 does not end there.
In October of this year, several vehicles belonging to the European Space Agency and united in the BepiColombo mission left the earth's limits. Robotic researchers of Mercury belong to several states, and astronomy plans include the complete study of the first planet from the Sun. It is assumed that Russia will also take part in the study of the smallest planet in our system after 2031; other walkthrough scientific works and their details are yet to be determined.
natural satellites
After terrestrial experts began to actively conduct observations of the "life activity" of Mercury, the detection of the alleged satellite became possible, and scientists have high hopes for this. At this stage of space exploration, the characteristic of planet #1 indicates that it is difficult for an object to form its own neighbor.
There are several reasons why Mercury does not have natural companions revolving in its orbit. First, the gravity of the object relative to the neighboring scorching star is small, and it cannot attract and hold even small asteroids. Secondly, strong solar winds intervene in the “capture” of the orbital prisoner, which constantly attack the small planet.
Perhaps in the distant past, when our universe was still being formed, Mercury had natural satellites. Millennia passed, and the impact of the fiery neighbor of the Sun broke the idyll of cosmic interaction, swallowing the hypothetical Mercury moons.
In addition to the question of the number of satellites, the second most popular question is how many rings the planet has. Modern data obtained from the Messenger apparatus indicate that Mercury does not only have satellites, but also rings.
The formation of neither one nor the other object of planetary significance in nature at this moment is impossible. This is due to the fact that body No. 1 is not located near the asteroid belt, like the red neighbor in the solar system Mars. Gravitational indicators do not attract large space bodies and Trojan asteroids into the orbit of the smallest planet.
talking plain language, the planet simply does not have the material to create rings or a satellite that accompanies it in cold starry space. The only visible ones with the given equipment settings are the rings of the planet's magnetic fields.
Finding a suspected satellite
There is a lot of controversy among astronomers regarding the moons of planet #1. Some cosmologists are sure that objects invisible in telescopes simply must exist. They argue that if you find a solution to a school physics problem with the condition “determine the first space velocity for a Mercury satellite flying somewhere in the bowels of the solar system,” then you get a reasonable answer to a centuries-old question. Knowing the mass and radius of object No. 1, using formulas, it is easy to determine that the required value is 2999.5 m per second.
The condition of another popular problem, which sounds like “calculate the period of revolution of the satellite of Mercury, located near the planet”, will help the curious to determine a tangible indicator of astronomical scale. Using the planetary values of the mass and radius of the object, we can calculate that the period of revolution is 85 minutes. For several years now, such puzzles have been popular among students who take the EGE.
double star
For a long time, astronomers of the Earth were haunted by the question of whose ultraviolet radiation he discovered in the early 70s. last century, the American apparatus "Mariner-10". After analyzing the available information, it became clear that the probe caught a "galactic hello" from the binary star 31, which is located in the constellation of the Chalice. The period of revolution of the star "minx" around its own star is almost 3 days.
No matter how scientists tried to determine who owns the second burst of cosmic radiation detected by Mariner 10, their attempts were unsuccessful. The question remained unanswered, and there is hope that in subsequent flights to the orbit of Mercury, knowledge about this planet will expand and be replenished with new facts.
Mercury is the first body in our solar system, the flight to which is one of the most difficult. This is explained by the close location of the object to our star. But astronomers do not give up hope that the planned missions to the smallest planet in the future will be successful and bring new knowledge about space.
