What is the moon made of? Our natural satellite is the moon. Orbital characteristics of the Moon

The Moon contains a metallic core! This is the conclusion reached by Rene Weber of the Marshall Center. space flights NASA and Rafael Garcia of the University of Toulouse re-examined data collected during the Apollo lunar mission in the late 60s and early 70s. Perhaps the opening will shed New World on the evolution of the Earth's satellite.

As part of the Apollo space program, four seismometers were delivered to the Moon, which recorded the seismic activity of the celestial body until 1977. It turned out that seismic shocks on the Moon occur much less frequently than on Earth. Moreover, since the surface of the earth's satellite is dotted with craters left over from collisions with small cosmic bodies, this distorts instrument signals and makes vibrations of the lunar crust less noticeable.

For a long time, information obtained from the Moon through seismic sensors was considered practically useless to scientists. However, over the past forty years, methods for analyzing seismic data have changed significantly. In addition, Weber and Garcia were able to take into account the “error” arising from craters. As a result, they came to the conclusion that the Moon, like the Earth, has a hot metal core. Its diameter is approximately 330-360 kilometers, it is surrounded by a partially molten shell with a diameter of approximately 480 kilometers. Inside the core, in turn, there is a solid iron core with a diameter of approximately 240 kilometers.

"We applied robust seismology to this data set, resulting in the first direct evidence of the lunar core," said cosmologist Rene Weber.

The researchers also analyzed the seismograms by processing the data into groups, which made it possible to determine the source of the seismic activity. By determining the trajectories of seismic waves and the characteristics of their reflection from the inner layers of the Moon, they were able to identify the composition and structure of the layers of the lunar core at various depths.

Scientists believe that due to the large amount of iron in the depths of the Moon, it has a powerful magnetic field. Although the lunar core is in many ways similar to the earth's, their structure is still different. As we know, the earth's core has a solid inner and outer liquid layer. And in the core of the Moon there is also a solid third layer, the boundary between the mantle and the outer liquid nuclear shell.

The Moon is believed by astrophysicists to have formed approximately 4.5 billion years ago as a result of the collision of the Earth with a large space object the size of the planet Mars. Hypothetically, this shock “knocked out” a piece from the Earth consisting of the crust of the molten mantle, which later turned into the Moon. Moreover, studies carried out at the Kola superdeep well established that the composition of the peninsula’s rocks is almost 90 percent identical to that of lunar rocks. It turns out that this happened in the place where the layers of crust were located, which later made up the Kola Peninsula.

Until recently, it was believed that the Moon was “cold” heavenly body, however, a mystery for scientists was the presence of a weak (residual) magnetic field. The fact is that, as they say scientific theories, its source on planets is tectonic activity. For example, near the Earth it is created by the movement of molten metal in the core.

In 1959, it was discovered that the Moon's magnetic field is not uniform. According to research by scientists from the Massachusetts Institute of Technology, the Moon at an early stage of its existence had a liquid core, and its magnetic field was similar to that of the Earth.

Now this phenomenon seems to be explained. In addition, since the mantle of the Moon, apparently, is also hot and convection of matter occurs in it (read more about this in the article “Volcanoes - the alarm level is growing”), then our satellite may contain volcanic activity. Indeed, the Japanese Kaguya probe discovered on the surface of the Moon, near the Marius Hills plateau, a hole with a diameter of about 65 meters and a depth of about 80 meters. According to scientists, this may indicate the existence on the Earth's satellite of tunnels laid by hardened volcanic lava flows. This hypothesis is also confirmed by the presence of winding grooves of unknown origin on the surface of the satellite.

The research results were presented at a recent meeting of the American Astrophysical Union. Its participants noted that knowledge about the composition of the lunar core will also help to better understand how our Earth was formed and how it will evolve in the future.

Diameter: 3476 km;

Surface area: 37,900,000 km²;

For many millennia Moon attracts a person's gaze. Ancient peoples, observing the Moon, personified it with a deity - as a night world luminary. The Romans called the satellite the Moon and Diana, the Greeks - Selene, the ancient Egyptians - Iyah. While observing the Moon, ancient people noticed the frequency of changes lunar phases- it grew and waned, disappeared completely and was certainly reborn again. The fickle queen of the night became the first measure of time, and the first lunar calendar was compiled, which is still used today.

Moon- the only one natural satellite Earth. The second brightest object in the earth's sky after and the fifth largest natural satellite of the planets. It is also the first and only celestial body, besides the Earth, visited by man. The average distance from the Moon to the Earth is 385,000 km, or just over one light second. The Earth's satellite is 50 times smaller than its planet, and its radius is 1738 km (27% of the Earth's radius). Our planet, due to gravitational forces, causes the Moon to rotate in an elliptical orbit at a speed of 1.02 km/s. On this moment the parameters of the lunar orbit are known with high accuracy. Our satellite makes a full revolution around it in 27.322 days or 27 days 7 hours and 43 minutes. This is the time that is called lunar month, which differs by 3 days from the calendar. Also gravitational attraction between the Earth and the Moon is the cause of the earth's ebb and flow.

Our satellite was formed 4.36 billion years ago. According to one version, the Moon and the Earth

formed at the same time from a gas-dust cloud. There is also

assumption that the Moon was formed as a result of the collision of the Earth

with another object

Lunar surface

Observing the Moon on its surface you can see dark spots various shapes. These spots date back to the 17th century. began to be called seas. In those days, it was believed that there was water on the Moon, which means there should be seas and oceans, like on Earth. They were given names that are used to this day: Ocean of Storms, Sea of ​​Cold, Sea of ​​Rain, Sea of ​​Clouds, Sea of ​​Tranquility, etc. However, already in 1753, the Croatian astronomer Ruđer Bošković proved that the Moon does not have an atmosphere, so on its surface Liquid water cannot be present, since in the absence of atmospheric pressure it would immediately evaporate. Lunar seas, which make up approximately 16% of the entire surface of the Moon, are huge craters resulting from collisions with celestial bodies that were later flooded with liquid lava.

Lunar landscape original and unique. The moon is all covered with craters of different sizes in diameter - from hundreds of kilometers to a couple of millimeters. There are two theories about the origin of these craters:

• volcanic theory - was put forward back in the 80s years XVIII V. German astronomer Johann Schröter, according to which lunar craters were formed due to powerful volcanic eruptions on a surface;
• meteorite theory - the craters were formed during the formation of the satellite when the Moon was subject to meteorite bombardment. Recesses formed on the lunar surface, which became known as craters.

A significant part of the lunar surface is dotted with craters of various sizes.

The photo shows the Copernicus crater, which was formed about 800 million years ago.

Its diameter is 93 km, and its depth extends almost 4 km.

Fragment of a section of the Moon's surface

The moon has no atmosphere, it is simply a round, rocky celestial body orbiting around. The sky above the Moon is always black, even during the day. There is no air-gas shell that would trap heat on our satellite. Therefore, on the Moon, as well as on, there are sharp temperature fluctuations at night and during the day. During the day, the lunar surface heats up to +120 °C, and at night or even in the shadow it cools down to −160 °C.

The full Moon reflects only 7% of the sunlight falling on it. Since the Moon does not glow itself, but only reflects sunlight, only the illuminated part of the lunar surface is visible from Earth. The Moon orbits the Earth, and thus the angle between the Moon and the Sun changes; we observe this phenomenon as a cycle of lunar phases.

Change of lunar phases. The period of time between full moons is called

lunar month and is 27.32 days

Structure of the Moon

The moon consists from the crust, upper mantle, middle mantle, lower mantle (asthenosphere) and core. The density of the Moon is 3346 kg/m³ - the same as that of the Earth's mantle. This means that our satellite either does not have a dense iron core, or it is very small. Indeed, the shell of the inner core is rich in iron, it has a radius of only 240 km, while the liquid outer core consists mainly of liquid iron with a radius of approximately 300-330 kilometers. By mass, the lunar core makes up only 2% of the total mass of the satellite and consists of iron alloyed with small amounts of sulfur and nickel. Around the core there is a partially molten boundary layer with a radius of about 480-500 kilometers. Like all planets, the Moon has the largest volume in its structure in its mantle. It can be divided into three components: the upper one with a thickness of 400 km, the middle one with a thickness of 700 km and the lower one with a thickness of approximately 200 km. The Moon's mantle is not completely melted like the mantle and therefore does not have volcanoes.

One of the sensations of lunar exploration was the discovery of a thick crust 60-100 km thick. This indicates the existence in the past on the Moon of the so-called magma ocean, in the depths of which melting and formation of the crust took place during the first 100 million years of its evolution. We can conclude that the Moon and Earth had a similar origin. However, the tectonic regime of the Moon differs from the plate tectonics regime characteristic of the melting basaltic magma used to build up the lunar crust. That's why she's so fat.

Internal structure of the Moon.

Core - 330 km;

Mantle - 1300 km;

Kora - 60-100 km

First steps on foreign land

Man has always been attracted to space. As soon as he looked at the night sky, he began to imagine himself as a traveler through the endless depths of the dark unknown, imagining how he would finally reach other worlds, walk on the extraterrestrial surface, perhaps find a new home for himself on other planets. However, no matter how hard humanity has tried until now, it has not yet been able to reach these new worlds. There are many reasons: some of them are located at enormous, by earthly standards, distances from our planet, while others have unsuitable conditions for staying on them, etc. Yet main reason is precisely the distance. Even the closest planet from Earth takes a modern probe at least eight months to get there. Who would dare to take such a risky and long journey, because it is still unknown how space will influence a person during such a long flight.

Nevertheless, the man did not give up, and although he had not yet managed to reach the nearest planets, he was still able to make his first space flight to the nearest and only Earth's satellite - the Moon.

Exploration of the Moon using spacecraft began on September 14, 1959, with the collision of the Luna-2 automatic station with the surface of our satellite. Until this point, the only method of exploring the Moon was by observing the Moon. Galileo's invention of the telescope in 1609 was a major milestone in astronomy, particularly in the observation of the Moon. Galileo himself used his telescope to study the mountains and craters on the lunar surface. At that time, in addition to the arms race, between the USA and the USSR there was an equally important rivalry in terms of lunar exploration. In 1962, the 35th US President John Kennedy formulated the main US mission in space as landing on the Moon.

Lunokhod-1—the first automatic rover on the Moon

Man on the Moon

> > What is the Moon made of?

Composition of the Moon– Earth’s satellite: description for children with photos, the structure of the Moon, what the core, mantle and crust consists of, what the surface looks like, seas, thickness of layers.

Begin explanation for children parents or teachers At school about the structure can be explained by the fact that the Moon is easiest to find in the sky. For a long time, people have been interested in dark and light spots on the surface. Let's take a closer look at what the Moon is made of, what layers and features of the satellite's surface are there.

Lunar surface - explanation for children

Children You probably remember fairy tales that said that the Moon was made of cheese. To explanation for children was clear, it should be noted that the more likely material is stone. The surface is covered with dead volcanoes, impact craters, lava flows, and spacecraft.

Ancient scientists believed that the dark areas were seas. In general, they can be called that, only in these formations there is no water. Important explain to the children that there are lava pools in front of them. At the very beginning of lunar history, the surface was in a molten state, giving rise to volcanoes. However, they quickly cooled, and the lava hardened. With asteroid attacks, it shattered, damaging the surface.

From the marks it can be judged that asteroids were frequent guests of the traveler. But children must understand that at the dawn of the formation of our system, all the planets collided and moved chaotically. On Earth, this is not so noticeable due to the movement of tectonic plates, as well as the atmosphere, which burned most of the spatial intruders. But there is no such protection on the Moon, so its surface clearly reflects the whole story.

The attack period ended 3.8 billion years ago, but all the craters remained. Large and small asteroids melted on the surface, but did so slowly, which blocked the lava flows.

For the little ones It should be said that the thin crust consists of regolith, reminiscent of concrete. When foreign objects crash into a surface, they tear it into small fragments, leaving an imprint (Neil Armstrong's mark).

The crust extends 60-100 km wide. Regolith can be shallow (3 m) in the seas or deep (20 m) in mountainous areas.

Beneath the Moon's Surface - Explained for Kids

Now you should take a closer look at the composition of the Moon. Like the Earth, the satellite has a crust, mantle and core. The latter consists of iron and is surrounded by a softer and liquid outer shell (500 km). But the inner core occupies only 20% of the entire Moon (50% for other rocky bodies).

Most of the inner layer is represented by the lithosphere (1000 km). Since the layer began to melt at the very beginning of lunar formation, magma broke through to the surface, creating plains. Gradually it cooled and completely stopped volcanic activity.

In terms of density, the satellite ranks second after Io (the moon of Jupiter). The presence of layering is most likely caused by crystallization of the magma ocean after formation.

The density of lunar rocks averages 3.343 g/cm3, which is noticeably lower than the average density for the Earth (5.518 g/cm3). This difference is mainly due to the fact that the compaction of matter with depth is much more noticeable on the Earth than on the Moon. There are also differences in the mineralogical composition of lunar and terrestrial rocks: the content of iron oxides in lunar basalts is 25%, and titanium is 13% higher than in terrestrial ones. “Marine” basalts on the Moon are distinguished by a higher content of aluminum and calcium oxides and a relatively higher density, which is associated with their deep origin.

Seismic methods were used to study the structure of the Moon. Currently, the picture of this structure has been developed in quite detail. It is generally accepted that the interior of the Moon can be divided into five layers.

The surface layer - the lunar crust (its thickness varies from 60 km on the half of the Moon visible from the Earth to 100 km on the invisible one) - has a composition close to the composition of the “continents”. Beneath the crust is the upper mantle - a layer about 250 km thick. Even deeper - the middle mantle is about 500 km thick; It is believed that it was in this layer that “marine” basalts were formed as a result of partial melting. At depths of about 600-800 km, deep-focus lunar seismic sources are located. It should be noted, however, that natural seismic activity on the Moon is low.

At a depth of about 800 km, the lithosphere (solid shell) ends and the lunar asthenosphere begins - a molten layer in which, like in any liquid, only longitudinal seismic waves can propagate. The temperature of the upper part of the asthenosphere is about 1200 K.

At a depth of 1380-1570 km, a sharp change in the speed of longitudinal waves occurs - here lies the border (rather blurred) of the fifth zone - the core of the Moon. Presumably, this relatively small core (accounting for no more than 1% of the Moon's mass) consists of molten iron sulfide.

The surface, rather loose, layer of the Moon consists of rocks crushed by a constant stream of falling particles. solids- from micrometeorites and dust to large particles - multi-ton meteorites and asteroids.

Above the surface of the Moon there is no gas atmosphere as such, since it cannot be retained by the Moon due to its low mass. As a result, even the lightest atoms at average thermal velocities are able to overcome the gravity of the Moon. Therefore, the density of gas above the Moon is at least 12 orders of magnitude less than the density of the surface atmosphere (although noticeably higher than the density of interstellar gas).

The uppermost layer is represented by the crust, the thickness of which, determined only in the areas of the basins, is 60 km. It is very likely that over large continental areas reverse side The moon's crust is approximately 1.5 times more powerful. The crust is composed of igneous crystalline rocks - basalts. However, in their mineralogical composition, the basalts of continental and marine areas have noticeable differences. While the most ancient continental regions of the Moon are predominantly formed by light rock - anorthosites (almost entirely consisting of intermediate and basic plagioclase, with small admixtures of pyroxene, olivine, magnetite, titanomagnetite, etc.), crystalline rocks of the lunar seas, like terrestrial basalts, composed mainly of plagioclases and monoclinic pyroxenes (augites).

Under the crust is the mantle, which, like the earth’s, can be divided into upper, middle and lower. The thickness of the upper mantle is about 250 km, and the middle is about 500 km, and its boundary with the lower mantle is located at a depth of about 1000 km. Up to this level, the velocities of transverse waves are almost constant, and this means that the subsoil substance is in a solid state, representing a thick and relatively cold lithosphere, in which seismic vibrations do not die out for a long time. The composition of the upper mantle is presumably olivine pyroxene, and at greater depths there is schnitzel and the mineral melilite, found in ultramafic alkaline rocks.

At the boundary with the lower mantle, temperatures approach melting temperatures, and strong absorption of seismic waves begins from here. This area is the lunar asthenosphere. At the very center, apparently, there is a small liquid core with a radius of less than 350 kilometers, through which they cannot pass. transverse waves. The core can be iron sulfide or iron; in the latter case it should be smaller, which is in better agreement with estimates of the density distribution over depth. Its mass probably does not exceed 2% of the mass of the entire Moon. The temperature in the core depends on its composition and, apparently, lies within the range of 1300 - 1900 K.

The Moon is the most accessible body in the world if you suddenly want to look at some space object with the naked eye. People have been very interested in the history of the appearance of dark and light spots on its surface throughout the history of mankind. What caused the formation of these strange features?

Children's fairy tales tell us about what is made from cheese. But what is also true for other bodies in solar system, stone is a more realistic candidate for this. The Moon's surface has dead volcanoes, impact craters and lava flows. Some of them can be seen without special instruments.
Ancient scientists believed that the dark areas of the Moon could be oceans. And that’s why they were called in Latin “mare”, which means “sea”. These areas are truly oceans in a certain sense. Instead of water, the lunar seas contain solidified lava. During the Moon's youth, its crust was warm enough to form volcanoes. Although at the same time it quickly cooled and hardened. Lava could break through the crust when large enough asteroids fell on the Moon.

There is much evidence of such asteroid impacts on the surface of the Moon. Early in the history of the solar system, all the planets and moons suffered from them. This was the so-called period of heavy bombardment. Plate tectonics and surface erosion have obscured much of the evidence for this period. In addition, the atmosphere helped burn up some small meteorites, preventing them from reaching the surface. However, the Moon does not have all these factors. Therefore, the history of the Solar System is preserved unchanged on the surface of the Moon.

The thickness of the Moon's crust is 60-100 km. Regolith on the surface can be shallow - up to 3 meters in the seas, and up to a depth of 20 meters in the hills.

Beneath the surface

Like the Earth, the Moon boasts earth's crust, mantle and core. Deep within its interior, the Moon may have a solid iron core surrounded by molten metal. The outer core of the Moon can be up to 500 km in size. However, the small inner core makes up only about 20 percent of the Moon, compared with the 50 percent core of other rocky bodies.

Most of the Moon's internal structure consists of the lithosphere, which is about 1000 km thick. As this area melted early in the Moon's evolution, it supplied magma to the lava plains on its surface. However, over time, the magma cooled and hardened, thereby stopping volcanism on the Moon.

The Moon is the second densest body in the Solar System after the satellite. The separation of its inner layers was probably caused by the crystallization of the magma ocean shortly after its formation.

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