Relief Moon briefly. §15.2

The lunar surface is lifeless and empty. Its feature is the complete absence of atmospheric effects that are observed on Earth. The night and day comes instantly as soon as the rays of the sun appear.

Due to the lack of medium for the propagation of sound waves, complete silence reigns on the surface.

The axis of rotation of the moon is inclined only by 1.5 0 from normal to ecliptic, so the moon has no seasons, changes of the year. sunlight Always almost horizontally in the lunar poles, which makes these areas constantly cold and dark.

The lunar surface varies under the influence of human activity, meteorite bombing, irradiation with high-energy particles (X-ray and space rays). These factors do not have a noticeable impact, but for astronomical times, the surface layer is strongly "plowed" - regite.

When the surface of the meteor particle is hit, a miniature explosion occurs and particles of soil and meteorite substance are scattered in all directions. These particles in most leave the gravitational field of the moon.

The range of daily fluctuations of the temperature is 250 0 S. varies from 101 0 to -153 0. But the heating and cooling of rocks occurs slowly. Fast temperature change occurs only with lunar eclipses. It was measured that the temperature varies from 71 to - 79 per hour.

The temperature of the catering layers was measured with radio astronomy methods, it turned out to be permanent at a depth of 1 m. And equal to -50 C from the equator. So the upper layer is a good heat insulator.

An analysis of the lunar breeds delivered to the Earth showed that they were never exposed to water.

The average density of the moon is 3.3 g / cm 3.

The period of circulation of the moon around the axis is equal to the period of its appeal around the Earth, so it is observed from the ground only one side. The reverse side of the moon was first photographed in 1959.

Light areas of the lunar surface are called continents and occupy 60% of its surface. These are uneven mountainous areas. The remaining 40% of the surface is sea. These are depressions filled with dark lava and dust. They were named in the 17th century.

The main collections are crossed by mountain ranges located along the coarse seas. The greatest height of the lunar mountains reaches 9 km.

Lunar craters have in most meteoric origins. There are few volcanic, but there are combined. The largest lunar craters have a diameter of up to 100 km.

Bright outbreaks were observed on the moon, which could be associated with volcanic eruptions.

The Luna has almost no liquid core, this is evidenced by the lack of magnetic field. Magnetometers show that the magnetic field of the moon does not exceed 1/10,000 ground.

Atmosphere:

Although the moon is surrounded by vacuum more perfect than one that it is possible to create in earthly laboratory conditions, its atmosphere is extensive and presents high scientific interest.

During a two-week lunar day, atoms and molecules, embedded by a number of processes from the lunar surface on ballistic trajectories, are ionized by solar radiation and then controlled by electromagnetic effects as plasma.

The position of the moon in orbit determines the behavior of the atmosphere.

The dimensions of atmospheric phenomena were measured by a number of instruments placed on the moon surface of Apollo astronauts. But the analysis of the data was difficult due to the fact that the natural lunar atmosphere is so insignificant that pollution from gases from Apollo significantly influenced the results.

The main gases presented on the moon are neon, hydrogen, helium, argon.

In addition to surface gases, a small amount of dust circulating up to several meters above the surface was detected.

The number of atoms and molecules in a unit of an atmosphere volume is less than the trillional fraction of the number of particles contained in the unit volume of the earth's atmosphere at sea level. The force of gravity of the moon is small to keep molecules at the surface.

Any body with a speed of 2.4 km / s will be released from under the gravitational control of the moon. This speed is a bit more mid speed Hydrogen molecules at normal temperature. Dyssipation of hydrogen occurs almost instantly. Dissipation of oxygen and nitrogen occurs slower, because These molecules are harder. For astronomically small periods of time, the moon is capable of losing their entire atmosphere if she was ever had.

Now the atmosphere is replenished from the interplanetary space.

M. Mendillo and D. Boygardner (Boston University) After analyzing the results of observations of the full lunar eclipse, 29.11.1993 came to the conclusion that the lunar atmosphere is 2 times extended (equal to 10 diameters of the moon) than previously thought.

It is not supported by non-shocks about the lunar soil of micrometeorites and elementary particles of solar wind (protons and electrons), but by exposure to it with light and thermal photons of solar radiation.

The main components are atoms and sodium and potassium ions, knocked out of the lunar soil. The atmosphere is very sparse, but sodium atoms are easily excited and radiated, so they are easy to detect them. (Nature 5.10.1995).

Origin:According to the prevailing modern theories, the moon was formed together with Earth from one planezimali. Scientists believe that the Moon was originally very close to the Earth, and J. Darwin wrote that the moon was once in contact with the earth and the period of circulation of the two bodies was about 4 hours. But this assumption seems unlikely. Many believe that the moon was formed at a distance significantly less than half of the modern. In this case, tidal waves on Earth would have to reach 1 km.

There are other theories. New proof of the hypothesis was found that the moon was formed from the collision of some kind of body from the earth.

According to the satellite of the Moon "Clementine", treated in Hawaiian Un-

those (USA), a map was drawn up percentage content Iron on the surface of the moon. It may vary from 0% in the mountains up to 14% at the bottom of the seas. If the moon had the same mineralogical composition as the Earth, then the iron would be much more. So it was unlikely to have formed from one protoplanetic cloud with Earth.

The huge areas on the reverse side of the moon do not contain iron, but covered with anorthosite, rock rich in aluminum. Clean anorthitis is rarely found on Earth.

Impact on the Earth: Americans R. Bolling and R. Seven studied data on

the global temperature distribution obtained from satellites between 1797 and 1994. It follows from the data that the Earth is warm when the moon is complete, and cold - when the moon in New Moon. With its light in the full moon, the moon heats the ground by 0.02 0 C. Even such temperature changes can affect the climate of the Earth. (Astronomy Now, May 1995).

The surface of the moon can be divided into types: old mountainous terrain with lots of volcanoes and relatively smooth and young lunar seas. The main feature of the reverse side of the moon is its mainland character.

Dark surface areas that we can see from the ground on the surface of the moon, we call the "oceans" and "seas". Such titles came from ancient times when ancient astronomers thought that the moon had the sea and oceans, as well as the Earth. In fact, these dark areas of the surface of the moon have been formed as a result of volcanic eruptions and they are filled with basalt, which is darker than those surrounding its breeds. The main lunaries are focused within the visible hemisphere, the largest of them - the ocean storms. It is adjacent to the sea of \u200b\u200brains from the northeast, the sea of \u200b\u200bhumidity and the sea of \u200b\u200bclouds from the south. In the eastern half of the disc from the Earth, the chain from the northwest to the south-east of the sea of \u200b\u200bclarity, a sea of \u200b\u200bcalm and a sea of \u200b\u200babundance. To this chain from the south, the sea of \u200b\u200bnectar is adjacent, and from the northeast - a sea of \u200b\u200bcrisis. Comparatively small in the sizes of the sea are located on the border of visible and reverse hemispheres - the sea East, the sea is edible, the sea Smith and the South Sea. On the back of the moon there is only one significant formation of a sea type - the sea of \u200b\u200bMoscow. On the surface of the lunar seas under certain conditions of lighting, winding elevations are noticeable, called shafts. The height of these predominantly gentle hills does not exceed 100-300 meters, but the length can reach hundreds of kilometers. The likely the theory of their formation is their occurrence when freeing the lava seas due to compression. On the lunar surface, several small marine types formations are relatively isolated from large formations, the name "Lakes" are called. Education bordering the seas and in the continuity areas are called "bays". The sea differ from the mainland areas of the low reflective ability of their substance of their surface, more stripped form of relief and a smaller number of large craters per unit area, - on average, in terms of unit area, the number of craters on the mainland surface is 30 times higher than the number of craters in the seas. Elements of relief include lunar mountains. They are represented by mountain ranges, the borders of most seas, as well as numerous ring mountains, called crater. Separate peaks and small mountain ranges located on the surface of some lunar seas are probably in most cases the dilapidated craters. It is noteworthy that on the moon, in contrast to the Earth, there are almost no linear mountain chains, like such as Himalayas, Andes and Cordillers on Earth.

Craterics

Craterity is the most characteristic feature of the lunar relief. There is an order of half a million crater with a size of more than 1 km. Due to the lack of atmospheric, water and significant geological processes, the lunar craters were actually not subject to change and even the ancient crater were preserved on its surface. The largest lunar craters are located on the back of the moon, such as Korolev, Mendeleev, Gershpruung and many others. In comparison with them, Crater Copernicus with a diameter of 90 km, located on the visible side of the moon seems very small. Also on the border of the visible side of the moon are giant craters, such as a streng with a diameter of 255 km and Darwin with a diameter of 200 km.

Nowadays, more than 35,000 large and about 200,000 small details are recorded on the moon cards.

In the formation of moon relief forms participated as domestic powersand external influences. Calculations of the thermal history of the moon show that soon after its formation, the subsoil was warmed by radioactive heat and is largely melted, which led to an intense volcanism on the surface. As a result, gigantic lava fields were formed and a certain amount of volcanic crater, as well as numerous cracks, ledges and other. At the same time, a huge number of meteorites and asteroids dropped to the surface of the moon in the early stages - the residues of the protoplanetic cloud, with the explosions of which crater arose - from microscopic wells to ring structures in a variety of dozen, and possibly to several hundred kilometers. Now meteorites fall on the moon much less often; Volcanism also stopped mainly, since the moon spent a lot of heat energy, and radioactive elements were transferred to the outer layers of the moon. The residual volcanism indicates the expiration of carbon-containing gases in lunar craters, the spectrograms of which were first obtained by the Soviet astronomer N.A. Kozyrev.

Over time, Galilean began to make maps of the visible hemisphere of the moon. Dark spots on the surface of the moon were called "seas" (Fig. 47). These are lowlands in which there is no water drop. The bottom of their dark and relatively smooth. Most of the surface of the moon occupy mountainous, brighter spaces. There are several mountain ranges, named, like the earth, Alps, the Caucasus, etc. The height of the mountains reaches 9 km. But the main form of relief are crater. Their ring shafts up to several kilometers high surround large round deposits with a diameter of up to 200 km, such as keys and Shikqard all major craters are given names in honor of scientists. So, on the moon there are crater quiet, Copernicus, etc.

In the full moon in the southern hemisphere, it is clearly visible in a strong Crater binoculars with a quiet diameter of 60 km in the form of a bright ring and diverting radially light rays. Their length is comparable to the moon radius, and they stretch, crossing many other crater and dark depressions. It turned out that the rays were formed by the accumulation of many small craters with light walls.

The lunar relief is better to study when the appropriate area lies near the terminator, i.e. the boundaries of the day and night on the moon, then the slighted shadows lit up long shadows and are easily noticeable. It is very interesting for an hour to trace the telescope for how near the terminator on the night side lights light dots - these are tops of the shafts of lunar craters. Gradually, light horseshoe floats from Darkness - part of the crater shaft, but the bottom of the crater is still immersed in full darkness. The rays of the sun, sliding all lower, gradually outlines and the whole crater. It is clearly seen that, the less crater, the more they are. They are often located chains and even "sit" each other. Late crater was formed on older shafts. In the center of the crater, a slide is often visible (Fig. 49), in reality it is a group of mountains. Crater walls are circled with terraces cool inside.

The bottom of the crater lies below the surrounding area. Consider carefully the appearance of the shaft and the central slide of the Crater Copernicus, photographed artificial companion Moon on the side (Fig. 50). From the ground, this crater is visible on top and without such details in general from the ground in the best conditions, crater up to 1 km in diameter are barely visible. The entire surface of the moon is exist with small crater - gentle depressions - this is the result of shocks of small meteorites.

Only one hemisphere of the moon can be seen from the ground. In 1959, the Soviet Space Station, flying past the moon, first photographed the hemispheres of the Moon invisible from the ground. It is fundamentally not different from the visible, but it is less than the "marine" depression (Fig. 48). Now compiled detailed maps This hemisphere on the basis of numerous photographs of the moon, made from a close distance by automatic stations, separated to the moon, artificially created devices were repeatedly descended onto its surface. In 1969, on the surface of the moon first sank spacecraft With two American astronauts. To date, several expeditions of the US cosmonauts visited the moon, which safely returned to Earth. They went and even traveled on a special all-terrain vehicle on the surface of the moon, installed and left different devices on it, in particular seismographs to register "lunalations", and brought samples of lunar soil. Samples were very similar to earthly rocks, but they also discovered a number of features characteristic of only moon minerals. Soviet scientists received samples of lunar breeds from different places with the help of automatic machines, which, on the team, they took the ground sample and returned to Earth. Moreover, Soviet lunisers were sent to the moon (automatic self-propelled laboratories, Fig. 51), which completed many scientific measurements and soil tests and the considerable distances passed through the moon are several tens of kilometers. Even in those places of the lunar surface, which they look smooth from the ground, the soil is replete with funnels and is illuminated by the stones of all sorts of magnitude. The lunokhod "Step by step", managed from the ground on the radio, moved taking into account the nature of the area, the type of which was transferred to the land on television. This is the greatest achievement of Soviet science and humanity, not only as evidence of the unlimited possibilities of human mind and technology, but also as a direct study of physical conditions on another heavenly Tele.. It is important and what confirms most conclusions that astronomers only did from the analysis of the light of the Moon, which comes to us from the distance of 380,000 km.

The study of the lunar relief and its origin is interesting for geology - the moon as if the museum ancient history Her barks, as the water and the wind do not destroy it. But the moon is not quite a dead world. In 1958, the Soviet astronomer N. A. Kozyrev noticed an alphonse selection of gases from the lunar subsoil in the crater.

In the formation of the relief of the Moon, in the apparently, internal and external forces took part. The role of tectonic and volcanic phenomena is undoubted, as there are lines of discharge, chains of crater, a huge dining area with slopes with the same as crater. There is a similarity of lunar crater with lavam lakes of the Hawaiian Islands. Less large craters were formed from shots of large meteorites. On Earth there is also a number of crater formed in the fall of meteorites. As for the lunar "seas", they, apparently, are formed by the carriages of the lunar bark and the outpouring of the lava of volcanoes. Of course, on the moon, as on earth, the main stages of the property took place in the distant past. Numerous crater discovered on some other bodies of the planetary system, for example, on Mars and Mercury, should have the same origin as lunar. Intensive crater education, apparently, is associated with a small force of gravity on the surface of the planets and with the affairs of their atmosphere, a little softening bombardment by meteorites.

Soviet space stations Installed the lack of a magnetic field and radiation belts and the presence of radioactive elements on it.

Schematic map of the largest details on the moon hemispheres facing land. Conceptual map of the reverse side of the moon, invisible from the Earth.

The relief of the lunar surface was mainly clarified as a result of perennial telescopic observations. The "lunar seas", occupying about 40% of the visible surface of the moon, are plain lowlands crossed by cracks and low winding shafts; Large craters on the seas are relatively small. Many seas are surrounded by concentric ring ridges. The rest, the lighter surface is covered with numerous craters, ring-shaped ridges, furrows and so on. Craters less than 15-20 kilometers have a simple cupid shape, larger craters (up to 200 kilometers) consist of a rounded shaft with steep internal slopes, have a relatively flat bottom, more in-depth than the surrounding area, often with a central slide. The heights of the mountains above the surrounding area are determined by the length of the shadows on the lunar surface or photometric method. In this way, plaster molds of scale 1: 1,0000 to most of the visible side were composed. However, absolute heights, the distance of the surface points of the moon from the center of the figure or mass of the moon are determined very uncertainly, and the plaster-based plaster cards give only a general idea of \u200b\u200bthe relief of the moon. Much more and more accurately studied the relief area of \u200b\u200bthe moon, which, depending on the phase of the libration, limits the moon disk. For this zone, German scientist F. Hein, Soviet scientist A. A. Nefedyev, American scientist Ch. Wats made up plasterometric cards that are used to account for the irregularities of the moon edge with observations in order to determine the coordinates of the Moon (such observations are made by meridian circles and photos of the moon Against the background of surrounding stars, as well as over the observations of stars). Micrometric measurements are determined with respect to the lunar equator and the middle meridian of the moon selenographic coordinates of several main reference points, which serve to bind a large number of other points of the moon surface. The main source point at the same time is a small correct shape and well-visible near the center of the lunar disk crater masting. The structure of the moon surface was mainly studied by photometric and polarimetric observations, complemented by radio astronomy studies. Moon Soil Phase Tide

Craters on the lunar surface have a different relative age: from ancient, barely distinguishable, strongly recycled formations to very clear in the outlines of young craters, sometimes surrounded by light "rays". At the same time, young craters overlap more ancient. In some cases, the craters are embedded into the surface of the lunar seas, and in others - the rocks of the seas overlap the craters. Tectonic breaks, then cut the crater and the sea, they themselves overlap with younger formations. These and other relations make it possible to establish a sequence of different structures on the lunar surface; In 1949, the Soviet scientist A. V. Khabakov divided lunar education into several consecutive age-related complexes. The further development of this approach made it possible by the end of the 60s to compile medium-scale geological maps to a significant part of the surface of the moon. The absolute age of lunar formations is known only at several points; But, using some indirect methods, it is possible to establish that the age of the most young large craters is dozens and jups of millions of years, and the bulk of large craters arose in the "Domor" period, 3-4 billion years ago.

The formation of moon relief forms took part in both domestic powers and external influences. Calculations of the thermal history of the moon show that soon after its formation, the subsoil was warmed by radioactive heat and is largely melted, which led to an intense volcanism on the surface. As a result, gigantic lava fields were formed and a certain amount of volcanic crater, as well as numerous cracks, ledges and other. At the same time, a huge number of meteorites and asteroids dropped to the surface of the moon in the early stages - the residues of the protoplanetic cloud, with the explosions of which crater arose - from microscopic wells to ring structures in a variety of dozen, and possibly to several hundred kilometers. Due to the lack of atmosphere and hydrosphere, much of these crater has been preserved to this day. Now meteorites fall on the moon much less often; Volcanism also stopped mainly, since the moon spent a lot of heat energy, and radioactive elements were transferred to the outer layers of the moon. The residual volcanism indicates the expiration of carbon-containing gases in lunar craters, the spectrograms of which were first obtained by the Soviet astronomer N. A. Kozyrev.

Due to the lack of medium for the propagation of sound waves, complete silence reigns on the surface.

The axis of rotation of the moon is inclined only by 1.5 0 from normal to ecliptic, so the moon has no seasons, changes of the year. Sunlight is always almost horizontally in the lunar poles, which makes these areas constantly cold and dark.

An analysis of the lunar breeds delivered to the Earth showed that they were never exposed to water.

The average density of the moon is 3.3 g / cm 3.

The main collections are crossed by mountain ranges located along the coarse seas. The greatest height of the lunar mountains reaches 9 km.

Lunar craters have in most meteoric origins. There are few volcanic, but there are combined. The largest lunar craters have a diameter of up to 100 km.

Bright outbreaks were observed on the moon, which could be associated with volcanic eruptions.

The moon almost does not have a liquid core, this is evidenced by the absence of a magnetic field. Magnetometers show that the magnetic field of the moon does not exceed 1/10,000 ground.

Atmosphere:

Although the moon is surrounded by vacuum more perfect than one that it is possible to create in earthly laboratory conditions, its atmosphere is extensive and presents high scientific interest.

The position of the moon in orbit determines the behavior of the atmosphere.

The main gases presented on the moon are neon, hydrogen, helium, argon.

In addition to surface gases, a small amount of dust circulating up to several meters above the surface was detected.

Any body with a speed of 2.4 km / s will be released from under the gravitational control of the moon. This speed is slightly larger than the average speed of hydrogen molecules at normal temperature. Dyssipation of hydrogen occurs almost instantly. Dissipation of oxygen and nitrogen occurs slower, because These molecules are harder. For astronomically small periods of time, the moon is capable of losing their entire atmosphere if she was ever had.

Now the atmosphere is replenished from the interplanetary space.

There are other theories. New proof of the hypothesis was found that the moon was formed from the collision of some kind of body from the earth.

According to the satellite of the Moon "Clementine", treated in Hawaiian Un-

those (USA), a map of the percentage of iron on the surface of the moon was compiled. It may vary from 0% in the mountains up to 14% at the bottom of the seas. If the moon had the same mineralogical composition as the Earth, then the iron would be much more. So it was unlikely to have formed from one protoplanetic cloud with Earth.

The huge areas on the reverse side of the moon do not contain iron, but covered with anorthosite, rock rich in aluminum. Clean anorthitis is rarely found on Earth.

Impact on the Earth: Americans R. Bolling and R. Seven studied data on