Mercury is the smallest planet of the solar system and closest to the sun, called Mercurian in Latin relative to the Roman god of trade, and called the planet Mercury: the source of the label – the tongue of the Arabs – chasing and steady any sequence in his life, and also fast running and hence the name of the planet Mercury, which symbolizes the speed of rotation The planet around the sun.
Its diameter is about 4,880 km and its mass is 0.055 of the mass of the Earth and its orbit around the Sun is at 87.969 days. Mercury has the highest orbital anomalies among all the planets of the solar system, and has the smallest axial axis of these planets, completing three cycles around its axis for each orbital cycle. Mercury’s orbit changes in its orbital motion at a rate of 43 arc minutes per century, explained by Albert Einstein’s general theory of relativity at the turn of the twentieth century.
Mercury appears brilliantly when seen from the Earth, with an apparent range of -2.3 to 5.7, but it is not easy to see when it is in the 28.3-degree maximum elongation angle to the sun. Since Mercury cannot be seen in the glare of the day unless there is an eclipse of the sun so it can be seen at dawn and twilight.
The information available about Mercury is relatively low since terrestrial telescopes only reveal the crescent of the Mercury surface. The first space probe to visit Mercury is Mariner 10, which has dropped maps of about 45 percent of its surface from 1974 to 1975, while the second was by Messinger, which added 30 percent of the planet’s maps when it hit it on January 14, 2008
Mercury resembles the earth’s moon in its shape, with many shock nozzles and soft smooth areas. It has no natural moons or atmosphere. But it has an iron nucleus unlike the moon, resulting in the generation of a magnetic field equal to 1% of the value of the Earth’s magnet field. The density of this planet is an exception to its size due to the large size of its nuclei, and the temperatures are very variable and range from 90 to 700 Kelvin.
Mercury is small, some of the larger satellites, like Ganymede and Titan, are larger. Mercury’s composition is 70% metal and 30% silicate. Its density is the second largest in the solar system and is less than 5,515 g / cm كثافة. Scientists use Mercury’s intensity to determine its internal structure. They say that due to the size of the small planet and the non-compression of its internal components, its nuclei must be large in size and mostly composed of iron.
Mercury is dated to the first millennium BC. Greek astronomers believed that the planet was a separate planet, before the fourth century BC, and called one of these criminals the name “Apollo”, and thought that it appears only when the sunrise, and called the other name “Hermes”, and thought that no It can only be seen at sunset. The astronomical symbol of Mercury is derived from the legendary pagan form of the Greek god of commerce Hermes.
Mercury is considered the dominant planet in the constellations of the Gemini and the Virgo Tower according to astrology, where it is said that its cosmic influence is in the face when it passes through these constellations, affecting the chances of people born during this time. Ancient astronomers believed that ” Solitudo Hermae Trismegisti ” was a key feature of the planet, where it was said to cover almost a quarter of a quarter of the south-east.
The Arabs referred to the planet Mercury as a “stalker” and a “stalker”, a symbol of the great speed of the planet around the sun. In the eleventh century AD, the Andalusian astronomer Ibrahim In the twelfth century, Ibn Bajah spotted two dark spots on the surface of the sun. Later, Qutb al-Din Shirazi suggested that these two spots were only the crossing of Mercury and Venus. In the thirteenth century.
The apparent magnitude of Mercury is between -2.3 (more glossy than the Yamani’s hair) to +5.7, and the maximum amount of apparent magnitude when it is close to the sun in the sky. The observation of Mercury is complicated because of its proximity to the sun, so that it is difficult to monitor because of its glare, and can be seen for a short time at dawn and dusk, and Hubble Space Observatory has not been able to see it at all until now because of preventive measures that prevent it from being directed near the sun. Mercury can be seen from the southern half Of the Earth more easily than its vision of the northern half.
Explore Mercury by Terrestrial Telescopes
It was the first observation of Mercury by the telescope in the seventeenth century by Galileo Galilei, who observed the phenomenon of the planetary phase when he watched the Venus, but his telescope was not strong enough to see the Mercury phase. Pierre Gassendi made a telescope in 1631 that controlled the passage of the planet in front of the sun, as predicted by Johannes Kepler. Giovanni Battista Zubi in 1639 was able to detect and discover that Mercury has orbital phases similar to Venus and Moon, and this observation clearly demonstrated Mercury’s rotation around the Sun.
One of the rare astronomical events is the passage of one planet in front of the other, called the phenomenon of occlusion, and Mercury and Venus disappear once every few centuries. The only astronomical observation of this event took place on May 28, 1737, and was observed by the scientist John Pfeis at the Royal Observatory in Britain. The next blockage is expected on December 3, 2133.
In 1800, Johann Schrotter was able to observe some of Mercury’s surface, capturing 20 kilometers of high mountains. Frederick Bissel then used observations to get the wrong estimate of the 24-hour orbital orbit and the 70-degree pivotal tilt. In 1880, Giovanni Iscarielli drew more accurate maps of the Mercury surface and suggested that the rotation period was 88 days, the same period of astronomical rotation due to the restriction of tidal forces. This phenomenon can also be observed for the moon, known as synchronous motion. The mapping efforts of Mercury were later followed by Ignos Antoniadi, who published a book in 1934 containing all his maps and observations of Mercury. Many of the properties of the planetary surfaces, especially the whiteness, were taken from this book.
A team of Soviet scientists of the Institute of Radar and Electronics Engineering at the Soviet Academy of Sciences in 1962 sent radar waves and observed the surface of Mercury, the first discovery of radar by radar. Three years later, an American scientist named Gordon Bettinger used the radio telescope of the Caspian Arecibo telescope to monitor the planet’s rotation This would resolve the matter for a period of 58 days. So the theory of synchronized motion of Mercury became widely accepted. But the dilemma scientists faced was that if Mercury were exposed to tidal forces, the heat of the dark surface would have been much colder than those obtained from the emission of radio waves. However, scientists refused to drop the planet’s motion theory and explained it with alternative theories such as thermal energy distribution By wind.
An Italian scientist named Joseph Colombo observed that Mercury’s orbit was two-thirds of its orbital cycle, suggesting that the axial and orbital rotation periods would be 3: 2 rather than 1: 1. The information subsequently available by Mariner 10 confirmed the validity of this hypothesis, It means that the Schiaparelli maps and Antoniunade are correct. The earth observation did not show much of the inside information about Mercury, and the correct knowledge about Mercury only deepened when flying over it.
Space trips to Mercury
|Starship||the event||Date||Space Agency|
|Mariner 10||Launched||November 1973||NASA|
|The first approach||in March 1974|
|Second approach||September 1974|
|The third approach||March 1975|
|The first approach||14 January 2008|
|Second approach||6 October 2008|
|The third approach||30 September 2009|
|Put on orbit||March 2011|
|Bbay Colombo||Launched||Chartered in August 2014||European Space Agency / Japan Space Research Organization|
Access to Mercury poses many technical challenges, as the planet is very close to the sun, and the spacecraft that travels from Earth must travel 91 million kilometers towards the sun and its attractiveness. Mercury has an orbital velocity of 48 km per hour, while the Earth has an orbital velocity of 30 km per hour, so the spacecraft must change its speed dramatically so that it can access the Hawman transit orbit near Mercury.
Mariner probe 10
The Mariner 10 was the first spacecraft to visit Mercury, and was launched by NASA in 1975. The vehicle used Venus’s gravity to equate its orbital speed and was able to approach Mercury as the first vehicle to use gravity acceleration technology. NASA’s first spacecraft visited more than The Mariner 10 took the first images close to the surface of Mercury, which immediately showed images of many of the shock nozzles on its surface, revealing many of the geological terrain of its surface such as the Great Regiment, which was subsequently attributed to the few displacements in the cold iron nucleus. Mariner 10 during the orbital period, revealed the same face of the planet, which was close to him, making note both sides of the planet impossible, and therefore that the planet maps were not enough, and was profiling 45% of Mercury’s surface only.
The first flight of the Mariner 10 over Mercury was on March 29, 1974, and two days before it began recording large amounts of ultraviolet radiation near the planet. This led to the belief that there was a natural moon. Star number 31 in the constellation of mysticism.
Mariner 10 managed to make three approaches from Mercury, and the nearest one was 327 kilometers above its surface. At its first close, Mariner spotted 10 magnetic fields, which was a geological surprise to scientists due to the slow rotational speed responsible for generating the dynamo property. In the third approach, many data on magnetism were found which revealed that the magnetic field of Mercury is similar to the earth’s magnetic field and is responsible for solar wind deflection. However, the magnetic field strength of Mercury is 1.1% of the Earth’s magnetic field strength. The magnetic field of Mercury is still under study and many theories.
The Mariner 10 fuel was executed 8 days after the last approach from Mercury on March 24, 1975. Its orbit can no longer be properly controlled and the probe’s mission is terminated. It is believed to be still circling the Sun and approaching Mercury every few months.
The mission was NASA’s second mission to explore Mercury. The task included exploring the surface of Mercury and its geochemical space environment. The probe was launched on August 3, 2004, from Cape Canaveral Air Force Base on the Boeing 2 Delta. It made its closest approach to Earth in August 2005 and the October 2006 launch. In June 2007, it entered the orbit of Mercury. Mercury occurred on January 14, 2008, the second on November 6, 2008, and the third on September 29, 2009. It is expected that it will then enter orbit around the planet in March 2011.
Exploration of the Colombian Bistro
The European Space Agency (ESA) and Japan are planning to launch a space flight called BBI Colombo, which consists of two probes: the first to provide details and maps of the planet’s terrain and the second to study the magnetic envelope. It is expected to be launched in 2014 and Mercury will arrive in 2020.
The internal structure of the planet Mercury
Mercury is one of four rocky planets in the solar system, and its rocky body resembles Earth. It is the smallest planet in the solar system, with a tropical radius of 2,439.7 km. Mercury is the smallest of the two large satellites in the solar system, Ganymede and Titan. Mercury is 70% of the metal structure and 30% of the silicate. Mercury is the second highest density in the solar system, equal to 5.427 grams / cubic centimeter, just below the Earth’s density of 5.515 g / cm. The materials made up of Mercury become the most dense, equal to 5.3 g / cm2, corresponding to the Earth at 4.4 g / cm3.
Mercury density can be used to infer details of the internal structure. The outer layers of a non-gaseous planet are composed of lighter materials such as silicate rocks. As the depth increases, the density increases due to the pressure exerted by the outer rock layers and the different composition of the internal materials. The high-density habitat of non-invasive planets is likely to be mostly iron. While the density of the earth does not meet the purpose of knowing its internal structure due to the effect of gravity pressure. Mercury’s nucleus is generally not strongly compressed. Therefore, since it has such a high density, the nucleus must be rich in iron.
Scientists estimate that Mercury’s nucleus forms 42% of the planet’s total size, while Earth’s nucleus forms only 17% of the Earth’s total size. Modern scientists believe that Mercury’s nucleus is a molten nucleus. The nucleus is surrounded by a silica jacket with a thickness of 500 to 700 km. Based on the data collected by the Mariner 10 probe and observation through ground monitoring, the outer crust of the planet is believed to be between 100 and 300 km . One of the most important features of Mercury’s surface is the huge amounts of narrow edges on its surface, which extend for several kilometers and formed from the nucleus that cooled over time when the crust began to form.
Mercury contains more iron than any other planet in the solar system, and several theories have been proposed to explain it. One of the most important theories is that Mercury’s basic structure contains metal silicate similar to the Kondrite meteorite, which is thought to exist largely in the solar system.
There are three theories of iron formation in Mercury:
The first theory
Assumes that Mercury was at some point in its history the subject of many collisions with meteorites and miniature planets and that this collision left a proportion of its components in the outer shell, a process similar to what happened in the Earth and the Moon.
The second theory
Begins with the formation of Mercury from the solar nebula, and this nebula contains all elements before settling outside the solar energy. The planet’s mass was initially twice as large as the current mass, and the temperature from the initial star to Mercury was 2,500 to 3500 Kelvin. It could have reached about 10,000 Kelvin, so most of Mercury’s fossil components evaporated and formed an air envelope from the atmosphere Which evaporated away from the planet because of the solar wind. The evaporation of the material was the low-density material, while the high-density materials (such as iron) remained.
The third theory
Assumes that the composition of the solar nebula is very different from that of Mercury. This difference is more than predicted by the theoretical models, so that the elements in the disk orbits condense into the solid state at different distances from the star by their specific density. Heavy metals with a high solubility point – such as iron, nickel and silicon – are converted to solid state the closer they are to the star.
Mercury’s surface is very similar to that of the Earth’s moon and shows dark spots called moon seas similar to those on the moon, formed by volcanic activity, and large drilling, which shows its geological activity billions of years ago. Since information about Mercury’s terrain is derived from the Mariner 10 and Earth observation, the knowledge is less accurate than the rest of the planets. Currently, the information obtained from the data of the Sanger probe increases the human knowledge of this planet. For example, the discovery of an unusual, It has the name “Spider”.
The properties of whiteness indicate the existence of regions with different reflections, and therefore Mercury has different terrains of mountains, plains, valleys, hills and slopes. Mercury was subjected to meteoric bombardment and asteroids shortly after it was formed 4.6 billion years ago and may later be exposed to the so-called heavy bombardment of 3.8 billion years ago. During this period many comets were formed and collisions took place on its entire surface. The volcanoes formed some different terrain. The surface of the craters is indicated by the internal activity of the planet due to the monitoring of various terrain from mountainous and coastal chains and valleys that cut the craters.
One of the most famous features of the surface is two hot zones where the temperature reaches the highest value, is located in one of the most famous nozzle, the basin “Caloris” estimated at four thousand million years and is believed to be caused by a huge collision occurred on the surface of the planet in this region, heat, Calorie , where the average temperature up to a maximum of 430 degrees Celsius when the basin is at rock bottom and against the sun directly.
On the opposite side of the basin directly on the other side is a region with irregular irregular heights and terrain covering 360 thousand square kilometers of the planet’s area and consists of valleys, hills and mountains up to two kilometers called the strange land (Weird terrain), which believes that the waves resulting from the collision The cause of the Kaloris nozzle is the reason why this area is formed on the opposite side.
Collapsible tanks and collision nozzles
The nozzles appear in a variety of ways, from small-sized nozzles with a little like a saucer, to multi-ring nozzles that cross hundreds of kilometers. As shown in all geological conditions from new nozzles to collapsed craters. The nozzles on Mercury ‘s surface differ from those on the moon in that the area covered by the shells is smaller because Mercury’ s surface gravity is large.
The largest crater known as the “Caloris Basin”, with a diameter of about 1,300 km, is seen as a huge mare. The shock was caused by a flat basin with smaller, more recent shocks. Based on the estimate of the rate at which the projectiles hit the planet, the distribution of the size of these craters indicates that the impact on the Caloris formation occurred approximately 3.6 billion years ago, and the shock was so intense that the surface of Mercury’s face was torn. In fact, the area opposite Kaloris contains many cracks and cracks. The result of this shock was the emergence of lava formed rings centered around the crater for two kilometers on the perimeter of the nozzle.
About 15 collisions were filmed in the part taken from Mercury, and a 400-km polygonal basin is seen as the Tolstoy Basin. The Beethoven basin also has a diameter of 625 km.
Plains of Mercury
There are two distinct coastal areas on the surface of Mercury:
Gently rolling plains and ridgey plains located between the nozzles. It seems that these plains located between the nozzles have blotted many early-formed nozzles. This is evident because of the scarcity of nozzles with a diameter of less than 30 km. It is not clear whether this occurred as a result of volcanic activity or collisions. The plains are distributed between the drilling on almost the entire surface of the planet.
The flat plains, which are wide flat areas, fill the depressions extensively and are very similar to the Moon Sailors. It is worth noting that it fills a wide circle surrounding the Caloris basin. The main difference between these plains and the moon’s seas is that these plains within the nozzles have a single white value. Although there is no volcanic activity, the lobed ring shape of these plains is strongly supported by the volcanic foundation theory of these plains. All flat plains were formed after the formation of the Kaloris basin.
On the surface of Mercury, there are also transverse incisions of unknown origin, in the form of patterned lines, mostly from north to south, from north-east to south-west and from north-west to south-east. One of the explanations for these features of chess is that the crust hardens when the planet revolves around its axis much more rapidly, and perhaps its length is only 20 hours. Because of this rapid rotation, it is likely to be a tropical bulge of the planet; and after its rotation slowed down and its current role was played, gravity withdrew this swelling, transforming the shape of the planet into a sphere. These cross-linear features may have arisen when the surface undergoes this change. Since the creases do not cut off the Kaloris nozzle, this indicates that these creases were found before the shock.
Climate on Mercury
The average temperature of the sun’s exposed face in Mercury is 442.5 Kelvin, despite the large variation between minimum and high temperatures ranging from 100 Kelvin to 700 Kelvin, due to the lack of the atmosphere and the sharp drop in temperature between the equator and the poles.
The temperature in the sun-exposed area reaches 700 Kelvin perpendicular and drops to 550 Kelvin during the Apogee, while the darker side is about 110 Kelvin. The solar radiation intensity of Mercury ranges between 4.59 and 19.61 times the solar beam constant of 1.370 W / m2.
The possibility of ice
The presence of a thin layer of water ice in the bipolar region was concluded by radar monitoring. Due to the small deviation of the rotation axis, which is practically vertical on its orbit. Thus many of the electrode nozzles remain in the shade. The possibility that the temperatures in these areas with the eternal night to – 160 degrees Celsius is a high probability. In such circumstances, ice may exist. Experts say that the presence of water molecules on Mercury is the result of the collision of comets containing water or ice. There is also a theory of large amounts of water flows from the inner layers of Mercury, which evaporates in areas far from the poles to be lost in outer space. It believed that ice areas containing 10 14 -10 15 kg of ice, and the approximation of the Antarctic ice contains the amount equal to 10 × 4 18 kg , while the Antarctic Mercury contains 10 16 Kg.
Mercury is a very small planet, and because of this its mass and therefore its attractiveness is far less than it has a significant atmospheric atmosphere, and its proximity to the sun and its extreme heat make the atmosphere of the atmosphere quick and easy. However, it has a thin outer envelope, consisting of hydrogen, helium, oxygen, sodium, calcium, potassium and other elements. The outer layer is the upper layer of the atmosphere, but its decay on Mercury and the absence of other layers make astronomers It does not have an important air cell compared to other planets.
But the atoms of its outer shell are not stable. They constantly escape its attractiveness (mainly because of the solar wind) and are replaced by different sources such as the solar wind itself, ashes and debris thrown from the surface by collisions. In 2008, water vapor was discovered in the atmosphere of Mercury, believed to be the result of the evaporation of hydrogen atoms and oxygen in the atmosphere. The atoms of hydrogen and helium may come into its atmosphere from the solar wind, where Mercury temporarily captures it before re-entering space because of its weak attractiveness. There are no clouds, winds or other meteorological events on Mercury.
In his first days of birth 4.6 billion years ago, Mercury had an atmosphere, but shortly after its birth, its atmosphere was eroded and disappeared by the strong solar wind blowing on it due to its close proximity to the sun. The Mariner 10 detected very small amounts of helium at a height of 1,000 Over Mercury’s surface during its flight in 1974 and 1975, and the Mariner 10 data is also the first to prove the existence of a thin outer envelope of Mercury.
Magnetic field and magnetosphere
Mercury has a large magnetic field in spite of its small size and velocity around its slow (59 days) cycle. The value of this field according to the measurements taken by the Mariner 10 probe is approximately 1.1% of the Earth’s magnetic field strength and is equal in magnitude to the Mercury 300 Tesla equator. Similarly to Earth, the magnetic field of bipolar Mercury differs from the Earth’s magnetic field because the magnetic poles are very close to the axis of rotation. The measurements taken by Mariner 10 and Messinger showed that Mercury’s magnetic field is of constant value and shape.
Mercury’s magnetic field is likely to have arisen because of the dynamo effect of Earth. This effect is caused by the rotation of the iron-rich molten nucleus. The effect of strong tidal force due to the high orbital anomalies of the planet will maintain the nucleic fluid state needed to sustain the effect of the dynamo.
Mercury’s magnetic field is strong enough to harness the solar wind around the planet, forming a so-called magnetic envelope. Mercury’s magnetosphere is small compared to that of the Earth, but strong enough to limit solar wind plasma. This contributes to knowledge of the space wave of the planet’s surface. The Mariner 10 probe identified low solar plasma energy in the magnetosphere in the night portion of the planet. Explosions of active particles have also been detected in the planet’s magnetic envelope, indicating a high dynamic in the planet’s magnetic envelope.
During his second flight on October 6, 2008, Singer was able to detect the possibility of a leak of Mercury’s magnetic field in many ways. The probe has encountered a “whirlwind” of a magnetic field linked to the planetary magnetic field in interplanetary space and can reach 800 km. These storms arise when magnetic fields are connected to the solar wind by the magnetic field of Mercury. These solar-powered storms turn into a magnetic cyclone, forming windows within Mercury’s thermocouple and from which some solar wind can enter and affect Mercury’s surface. The process of connecting the interstellar magnetic fields to the magnetic reconnect is spread throughout the universe. This occurs in the Earth’s magnetic field, where magnetic cyclones are also generated. However, the recorded Missinger notes estimate that reconnecting to Mercury is ten times the Earth. Mercury’s proximity to the Sun represents about a third of the reconnection observed by Messinger.
Orbit and rotation
Mercury is the most planets in the orbital anomaly and has an anomaly of 0.21 and thus the distance between it and the Sun ranges from 46 to 70 million km. It takes Mercury 88 days to complete its orbit around the sun, which reaches its highest speed when it is near the bottom. The change in the central dimension of Mercury from the Sun signals a ring between self-rotation and orbital rotation of 3: 2, resulting in severe differences in the temperature of the planet’s surface.
The solar day on Mercury lasts 176 days on earth, almost twice as long as its orbital period. As a result, one year on Mercury is equivalent to half a day on Mercury or today Mercury passes through Mercury’s two planetary years.
Mercury orbits the Earth’s orbit seven degrees, which means Mercury’s passage through the Sun’s surface can occur when the planet crosses the Sun’s path and is at the same time between the Earth and the Sun. This is repeated on average every seven years.
Mercury’s central inclination is almost zero, and its best measured value was 0.027 degrees, the highest value among the solar system planets followed by the 3.1-degree buyer. Which means that for an observer standing on Mercury’s pole the sun will rise no more than 2.1 minutes arc from the horizon.
The resonance between self-rotation and orbital rotation
The orbital anomalies of Mercury according to Chaos theory vary from 0 to 0.42 millions of years due to the initial disturbance of other planets, and this is believed to explain the cause of resonance. A digital simulation has shown that the orbital resonance interaction with Jupiter may increase Mercury’s orbital anomalies to the point where it will collide with Venus five billion years later.
Mercury crossing the sun
A phenomenon through which Mercury can be seen from Earth like a black disk that crosses the sun disk. This phenomenon is repeated between 13 and 14 times in the century. This crossing can take place in May and November.
November is repeated every 7, 13 or 33 years, while the May crossing occurs only every 13 or 33 years. The last three episodes occurred in 1999, 2003 and 2006, and the next crossing will take place in 2016.
Mercury is during May transit near the apogee and the angle of the diameter is about 12 °. In November, Mercury will be near the bottom and the angle is 10 °.
Planet without moons
Mercury has no natural moons, and Venus and Venus are the only planets that do not have a satellite system. To answer the cause of the anomalies in these two planets, a hypothesis was suggested in the mid-1960s that Mercury was a moon of Venus and was able to escape from its orbit around Venus. Many computer simulations are currently being conducted to verify this hypothesis and the reasons for the possible escape. Such as the act of tidal force between the two planets may cause this escape, or because of the orbital spacing of the planets from each other.