There is no secret here: the periods of revolution of the Moon around its own axis and around the Earth are the same, and for this reason the Moon faces the Earth all the time with only one side. In other words, the Moon “turns” at the same speed as it “flies” across our sky, so at the same moment in time we can observe the same picture on its surface.
At the same time, it is not entirely correct to say that we see “one side” of the satellite of our planet - in fact, about 59% of the surface of the Moon is visible from the earth, that is, almost two-thirds of the lunar disk. We call that part of the Moon that is not visible to an observer from Earth far side of the moon.
The far side of the Moon was first photographed by the Soviet lunar station Luna 3 in 1959.
Why do they say that there are seas and oceans on the Moon?
We used to call the dark areas of the surface of the Moon that we can see from Earth “lunar seas.” In fact, of course, these “seas” do not contain (and never did contain) water, and the sonorous names came to us from antiquity, when ancient astronomers thought that the Moon, like the Earth, had its own seas and oceans.
In fact, the dark areas of the Moon's surface were formed as a result of volcanic eruptions and are filled with basaltic deposits that appear much darker than the surrounding rocks.
Moon Mountains
But there are mountains on the Moon, and the most real ones, and not only mountains, but also plateaus. Externally, they differ from the lunar “seas” and plains in that they are lighter in color.
The lunar mountains are similar to the terrestrial ones in appearance, but unlike them, they were formed not as a result of tectonic processes, but as a result of collisions of giant meteorites with the lunar surface.
What would the surface of the Moon look like if it had an atmosphere and gravitational force similar to Earth's (sweep)
Where do lunar craters come from?
On the surface of the Moon we can observe craters - evidence of bombardment of its surface by asteroids, comets and meteorites. There are about half a million craters larger than 1 km in size.
Due to the absence of an atmosphere, water and significant geological processes on the Moon, the lunar craters were virtually unchanged and even ancient craters were preserved on its surface. The largest crater on the Moon is located on the far side of the Moon; it measures 2240 km in diameter and 13 km deep.
What is regolith?
The surface of the Moon is covered with a layer of rock, crushed to a dusty state as a result of meteorite bombardment over millions of years. This breed is called regolith.
The thickness of the regolith layer varies from 3 meters in areas of the lunar “oceans” to 20 m on the lunar plateaus.
Is there water on the Moon?
No water was found in samples of lunar rock brought to Earth by astronauts participating in the Apollo mission and by Soviet lunar rovers.
However, we do know that the surface of the Moon has been bombarded by comets since its formation, and comet nuclei are known to be mostly made of ice. True, this does not add optimism - under the influence of solar radiation, water atoms should have disintegrated into hydrogen and oxygen atoms and, due to the weak gravity of the Moon, simply evaporated into outer space.
However, there is another point of view: as a result of mapping the surface of the Moon by the Clementine satellite, launched by NASA in 1994, craters were discovered in the polar regions of the Moon, which are always in the shadow, and in which water in the form of ice could be preserved.
Due to the great importance of the availability of water for the future colonization of the Moon, lunar bases are planned to be located in the circumpolar regions of our satellite.
The internal structure of our planet's satellite - the Moon
What's Beneath the Moon's Surface?
The structure of the Moon, like the structure of the Earth, includes several distinct layers: crust, mantle and core. This structure is believed to have formed immediately after the formation of the Moon - 4.5 billion years ago.
The thickness of the lunar crust is believed to be 50 km. Moonquakes occur within the thickness of the lunar mantle, but unlike earthquakes, which are caused by the movement of tectonic plates, moonquakes are caused by the tidal forces of the Earth.
The Moon's core, like the Earth's core, consists of iron, but its size is much smaller and is 350 km in radius. The average density of the Moon is 3.3 g/cm3.
Does the Moon have an atmosphere?
There is an atmosphere on the Moon - this is a fact, but it is so highly discharged that it can easily be ignored - this is also a fact.
One of the sources of the lunar atmosphere are gases that are released from the lunar crust, such gases include radon gas. Another source of gases in the lunar atmosphere are gases released when the lunar surface is bombarded by micrometeorites and the solar wind.
Due to the weak magnetic and gravitational field of the Moon, almost all gases from the atmosphere escape into outer space.
Where did the Moon come from?
There are several theories to explain the formation of the Moon. Until recently, the main assumption of scientists was that the Moon was formed as a result of centrifugal forces at the early stage of the formation of the Earth. As a result of these forces, some earth's crust was thrown into outer space and from this part the Moon was formed.
Due to the fact that, as scientists believe, throughout the history of the Earth, our planet has never had a sufficient rotation speed to confirm this theory, this point of view on the process of formation of the Moon is currently considered outdated.
Another theory suggests that the Moon formed separately from the Earth and was subsequently simply captured gravitational field Earth.
The third theory explains that both the Earth and the Moon were formed from a single protoplanetary cloud and the process of their formation took place simultaneously.
Although the above three theories of the formation of the Moon explain its origin, they all contain certain contradictions. The dominant theory of the formation of the Moon today is the theory of a giant collision of the proto-Earth with a planet-sized celestial body.
Is the Moon a satellite of the Earth or its “younger brother”?
The Moon is the largest satellite in the Solar System and in size it is only 4 times smaller than the Earth and only slightly inferior in size to Mercury. In this regard, some scientists consider the Earth-Moon pair not as a Planet-Satellite system, but as a double planet, since the size and mass of the Moon are quite large.
This is also supported by the fact that the center of rotation of the Earth-Moon system occurs not around the center of the Earth, but around the center of mass of both celestial bodies, which is located 1,700 km below the Earth's surface.
The mistress of the night sky has always attracted human attention. Numerous signs, rituals, and beliefs of people are associated with it. Many lunar secrets have already been revealed. However, interesting facts about the Moon, which scientists cannot unambiguously explain, continue to excite people’s minds.
- For the first time, areas on the Moon began to be sold by the American company The Lunar Embassy, founded by Dennis Hope, at a price of $20 per acre (approximately 4046 sq.m.). This American, having studied the UN Convention on Outer Space, concluded that it does not contain a single instruction banning the ownership of stars and planets by private individuals. In 1980 he proclaimed himself the owner of the Moon, Mars, Mercury, Io, Venus and began trading in “star” areas.
- Christopher Columbus, during his 4th expedition, used a total lunar eclipse to save his crew from starvation. It happened in America on February 29. The Indians of Jamaica, where the travelers were forced to spend a year, over time began to supply them with provisions worse. To frighten the aborigines, on the day of the eclipse, Columbus announced to them the wrath of the gods for their negligence and went to the ship’s cabin “to pray for forgiveness.” At the end of the eclipse, he announced that the Indians were forgiven. Food supplies have been resumed.
- The only person buried on the Moon is the famous American astronomer and geologist Eugene Shoemaker. Health problems prevented him from making interplanetary flights. After his death, his ashes were transported in a capsule by the Lunar Prospector interplanetary research station to the Moon in 1998.
- Due to the low gravity on the Earth's satellite, fine and hard lunar dust with the smell of gunpowder can penetrate everywhere. In astronauts it caused symptoms similar to hay fever. Penetrating into spacesuits and shoes, it significantly damaged them.
- The bloody "queen of the night" occurs during a total lunar eclipse. During this period, the Earth is on the same line between the Moon and the Sun. Light waves The red spectrum (as the longest) of sunlight, refracted in the earth's atmosphere, gives the “night sun” a crimson hue.
- The night luminary does not have its own magnetic field . However, the stones brought by the astronauts, nevertheless, magnetic properties possess. Where does this paradox come from? Scientists put forward 2 theories about this: the magnetic field disappeared due to the movement of the iron core of the Moon and its collision with meteorites.
- There are moonquakes on the moon, however, compared to earthly ones, they are very weak. Their maximum rating was 5.5 points on the Richter scale. The causes of lunar “earthquakes” have not yet been clarified.
- The “Fallen Astronaut” monument, measuring only 8 cm (by Paul Van Heijdonk), was erected on August 1, 1971. at the landing site of the Apollo 15 crew. The plaque next to it contains the names of 14 fallen space explorers. Among them is Yu. Gagarin.
- A "blue moon" is the second full moon in a calendar month.. It is observed once every 2.7154 years. The name of this event is determined not only by the color of the night star, but also by the translation of the English idiom “once in a Blue Moon”. In the Russian version, this corresponds to “after the rain on Thursday” (not soon or never).
- The difference in daily temperatures on the Moon ranges from -100°С to +160°С. On Earth, the record daily temperature drop occurred on January 23, 1916 in America (Montana): from +6.7 to -48.8 degrees Celsius.
- It became possible to see the far side of the earth's satellite only after October 7, 1959. On this day, the Soviet space station Luna 3 took its first photograph.
- Dark spots on the surface of the Moon that can be seen from Earth with the naked eye are called maria.. They are lowlands, the bottom of which is filled with dark solidified lava. There is no water in them. The first time a person set foot on the Moon was on the territory of the Sea of Tranquility on July 21, 1969.
- There are many craters on the moon. The giant among them is Hertzsprung, reaching a diameter of 591 km. It is located on the dark side of the Moon, so it is not visible from Earth. On visible side The largest crater on the Moon belongs to the Bayi crater (287 km).
- Where is the “far away kingdom, thirtieth state” familiar from children’s fairy tales located?? By simple calculations we get 3*9=27, 3*10=30. The first number is the sidereal period of the Moon's revolution around the Earth. 30 days is its synodic period (relative to the Sun).
- The Moon is moving away from the Earth by 4 cm per year. As a result, its orbit is not a circle, but a smoothly increasing spiral.
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What do we know about Moon? The Moon is the only natural satellite of the Earth, the second brightest object in our sky, and the only cosmic body that humans have set foot on besides the Earth. In most cases, you will only hear these 3 facts when you ask a random person about the Moon. It turns out quite strange, because throughout human history our gaze has constantly been turned to the Moon, it has constantly been the subject of controversy and discussion, a huge number of secrets and mysteries have hidden around it, many of which we have already solved, the other part remains to be revealed...
IN Ancient Egypt the moon was called " I", and in Ancient Greece - "Selena".
Question origin of the moon for a long time haunted scientists. Many different theories have been put forward: from the formation of a protoplanetary disk from the remains, to the capture of a passing asteroid by the Earth’s gravitational field. There were also completely contradictory and sometimes absurd theories, in the manner of artificial origin. The answer to the question of the origin of the Moon was found where it was least expected - underground at a depth of several kilometers. The rocks lifted from the bowels of the planet during the drilling of the Kola superdeep well were like two peas in a pod similar to those that the Soviet space automatic station delivered to Earth from the surface of the Moon in the early 70s. This marked the beginning new theory, which was confirmed and received public recognition only 30 years later - the Moon is a fragment from the collision of two young protoplanets of the Earth and Thea, which occurred 4.36 billion years ago at the dawn of formation solar system.
The Moon was created as a result of the largest collision in Earth's history. This happened 4.36 billion years ago at the dawn of the formation of the Solar System. The fragments from the collision were thrown into low-Earth orbit, where they remained under the influence of the gravitational interaction of the planet.
The young Moon found itself in an orbit 60,000 km from Earth. Every year the night star slowly but steadily moved away from the Earth - by about 4 cm per year. This was due to the gravitational interaction of the two bodies, forcing the Moon closer with each passage by the planet, but at the same time pushing Selene further away after each such approach. Today, the Moon's orbit is 384,467 km away. Based on this, it would be more correct to represent the trajectory of our satellite in the form spirals, moving along which the Moon is constantly moving away from us.
A visual diagram of the Moon’s movement (orbital changes) over the past 4.3 billion years.
Our generation and about a dozen generations before and after ours are, in a sense, very lucky - we can observe perfectly regular solar eclipses, such during which the Moon completely covers the solar disk, leaving only the corona. Nowadays, Selena is at an ideal distance from the planet; before, the distance was smaller and the Moon blocked the Sun along with the crown, turning the day into a dark night; in the future, the satellite will move away and will no longer be able to block the light of our star.
An ideal solar eclipse - the Moon completely covers the solar disk, but leaves the corona visible.
Over 100 years, an average of 237 solar eclipses, of which only 63 will be complete.
Only 63 of the 237 eclipses will be total, the rest will be partial or annular. The photo shows a partial eclipse.
The diameter of the Moon is 3476 km (at the equator, the polar diameter is 6 km less), which makes it the 5th largest satellite in the Solar System. The largest moon is Ganymede, orbiting Jupiter, with a diameter of 5264 km.
The Moon is the 5th largest satellite in the Solar System.
The internal structure of the Moon is similar to the structure of the planets terrestrial group(Mercury, Venus, Earth, Mars), it also consists of a solid inner and liquid outer core, a mantle and a solid crust on the surface.
Approximately 16% of the Moon's surface is occupied by so-called lunar seas. In reality, these objects have nothing in common with the seas; they are craters from fairly large-scale collisions with asteroids, comets and other space debris. The energy of such collisions was enough to cause massive eruptions of magma onto the surface, which solidified into a darker color than the rest of the landscape.
The Ocean of Storms is the largest dark gray region on the visible side of the Moon.
Have you ever noticed that the Moon appears much larger when low on the horizon than when it is high in the sky? This phenomenon is generally recognized and is called "", the effect is believed to manifest itself as a result of some kind of optical illusion, but the mechanism of its formation still remains a mystery.
Illusion of the Moon over the sea. Scientists have not yet been able to explain this interesting phenomenon.
One of the most interesting features of the Moon is that the period of its rotation around its own axis completely coincides with the period of rotation around the Earth. As a result, we only see one side of the Moon, always the same. Another, dark side, on the contrary, is always hidden from us. This phenomenon is called tidal capture, in the vastness of the Solar system, and the Universe as a whole, this is a fairly common phenomenon, for example, both satellites of Mars, all large satellites gas giants and many discovered exoplanets have synchronous rotation.
One of the first images of the dark side of the Moon
First dark side Humanity saw the moon on October 7, 1959 - the Soviet automatic interplanetary station " Luna-3"took the first photographs. The landscapes of the reverse side were strikingly different from the visible one, but did not stand out in anything special. From the photographs, the predominance of continents over the seas and the abundance of craters were determined, 9 of which were the largest on Selene.
And this is a modern photograph of the far side of the Moon
The most common misconception is: “there is no atmosphere on the Moon.” The Moon has an atmosphere! But it is extremely rarefied, its density is 10 trillion times less than that of Earth. Therefore, the sky on our satellite is always black, the Sun does not shine brightly there, and even during the day all the stars are visible.
The lunar atmosphere contains such an insignificant amount of gases that the sky is absolutely transparent.
The gravitational force of the Moon constantly influences the Earth and this influence is so great that slows down the planet(meaning the speed of rotation around its axis). So, on the young Earth 4.3 billion years ago, a day lasted less than 6 hours, 3 billion years ago - 9 hours, 100 million years ago, during the time of dinosaurs - 23 hours.
Over 4.3 billion years, the Moon has increased the Earth's day by 18 hours.
The gravitational force of the Moon is also responsible for ebb and flow. Every time Selene approaches Earth, it causes a tide, attracting water masses. And when it moves away, the tide ebbs. IN open ocean the maximum the water can rise to is 40 cm, but coastline as a result of the tidal wave reaching the bottom, the height can increase significantly.
The highest tidal waves are off the coast of Canada, their height reaches 18 meters.
For the globe, the magnitude of the gravitational force of the Sun is almost 200 times greater than the gravitational force of the Moon, but at the same time, the tidal forces generated by the Moon are almost twice as powerful as those generated by the Sun.
There were more than ten lunar rovers on our satellite, launched by the USSR, the USA and China. Several dozen space stations and probes explored the Moon, making many important discoveries and close-up photographs. Six manned expeditions were able to successfully land on the lunar surface. More than 380 kg of lunar soil was delivered to Earth.
NASA astronaut Edwin "Buzz" Aldrin became the second person to set foot on the Moon. 1969, Apollo 11 mission
It can also be noted that China has begun a long-term space program, which includes not only the landing of humans, but also the construction of inhabited lunar bases.
Chinese habitable lunar base project. It is not yet known exactly when this will become a reality, but China intends it very seriously.
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Perhaps every person has looked at the Moon at least once in his life. And even schoolchildren know certain facts about it. We have collected for our readers less well-known, but no less interesting facts about the satellite of our planet.
1. The moon was created as a result of a collision
The moon appeared as a result of a collision. Scientists believe that the Moon was formed from debris from the Earth and a space object the size of Mars after their collision.
2. 206 thousand 264 Moons
In order for it to be as light at night as during the day, about three hundred thousand moons would be needed, and 206 thousand 264 moons would have to be in the full moon phase.
3. People always see the same side of the moon
People always see the same side of the Moon. The Earth's gravitational field slows down the Moon's rotation around its axis. Therefore, the rotation of the Moon around its axis occurs in the same time as its rotation around the Earth.
4. The far side of the moon
The far side of the Moon is more mountainous compared to the one visible from Earth. This is explained by the force of gravity of the Earth, which has led to a thinner crust on the side facing our planet.
5. Moon Tree Seeds
More than 400 trees growing on Earth were brought from the Moon. The seeds of these trees were taken by the crew of Apollo 14 in 1971, orbited the Moon and returned to Earth.
6. Asteroid Cruithney
The Earth may have other natural satellites. The Cruithney asteroid moves in orbital resonance with the Earth and completes a full revolution around the planet every 770 years.
7. Craters on the surface of the Moon
Craters on the surface of the Moon were left by meteorites 4.1 - 3.8 billion years ago. They are still visible only because, geologically, the Moon is not as active as the Earth.
8. There is water on the moon
There is water on the moon. The Earth satellite has no atmosphere, but does have frozen water in shadowed craters and beneath the soil surface.
9. The moon is not a perfect ball
The moon is not actually a perfect sphere. It is rather egg-shaped due to the influence of Earth's gravity. In addition, its center of mass is not in the center cosmic body, and about two kilometers away from the center.
10. Crater named...
The lunar craters were first named after famous scientists, artists and explorers, and later after the names of American and Russian cosmonauts.
11. Moonquakes
On the Earth's satellite there are... moonquakes. They are caused by the gravitational influence of the Earth. Their epicenter is located several kilometers below the surface of the Moon.
12. Exosphere
The moon has an atmosphere called the exosphere. It consists of helium, neon and argon.
13. Dancing Dust
There is dancing dust on the Moon. It hovers above the surface of the Moon (more intensely at sunrise or sunset). Dust particles rise upward due to electromagnetic forces.
The Earth's satellite is more like a planet. The Earth and Moon are a double planet system, similar to the Pluto + Charon system.
15. The moon causes the tides on Earth
The moon causes the ebb and flow of the tides on Earth. The Moon's gravitational pull affects our planet's oceans. The highest tides occur during a full or new moon.
16. The Moon is moving away from the Earth
One lunar day is equal to 29.5 days on Earth. On the Moon, it takes 29.5 Earth days for the Sun to cross the entire sky.
19. "Ares I" and "Ares V"
Men haven't landed on the moon in 41 years. However, NASA is working on new rockets, Ares I and Ares V, that will be able to carry payload to the Moon and back.
20. Progress
Today, smartphones are much more powerful than the computers used to land the Apollo on the moon.
Especially for those who are interested in geography and interesting facts, we have collected.
Moon– satellite of planet Earth in the solar system: description, history of research, interesting facts, size, orbit, dark side of the Moon, scientific missions with photos.
Get away from city lights dark night and admire the beautiful moonlight. Moon- this is the only earthly satellite that has been rotating around the Earth for more than 3.5 billion years. That is, the Moon has accompanied humanity since its appearance.
Due to its brightness and direct visibility, the satellite has been reflected in many myths and cultures. Some thought it was a deity, while others tried to use it to predict events. Let's take a closer look at the interesting facts about the Moon.
There is no "dark side"
- There are many stories where the far side of the moon appears. In reality, both sides receive the same amount of sunlight, but only one of them is visible to earth. The fact is that the time of the lunar axial rotation coincides with the orbital one, which means it is always turned to us with one side. But we explore the “dark side” with spacecraft.
The Moon influences Earth's tides
- Due to gravity, the Moon creates two bulges on our planet. One is on the side facing the satellite, and the second is on the opposite side. These ridges cause high and low tides throughout the Earth.
Luna tries to escape
- Every year the satellite moves away from us by 3.8 cm. If this continues, then in 50 billion years the Moon will simply run away. At that time, it will spend 47 days on the orbital flyby.
The weight on the Moon is much less
- The moon yields to Earth's gravity, so you'll weigh 1/6 less on the moon. That is why the astronauts had to move by jumping like a kangaroo.
12 astronauts have walked on the moon
- In 1969, Neil Armstrong was the first to set foot on satellite during the Apollo 11 mission. The last one was Eugene Cernan in 1972. Since then, only robots have been sent to the Moon.
No atmospheric layer
- This means that the surface of the Moon, as can be seen in the photo, is devoid of protection from cosmic radiation, meteorite impacts and solar wind. Serious temperature fluctuations are also noticeable. You will not hear any sounds, and the sky always seems black.
There are earthquakes
- Created by earth's gravity. The astronauts used seismographs and found that there were cracks and breaks several kilometers below the surface. The satellite is believed to have a molten core.
The first device arrived in 1959
- The Soviet spacecraft Luna 1 was the first to land on the Moon. It flew past the satellite at a distance of 5995 km, and then entered orbit around the Sun.
It is in 5th position in size in the system
- In diameter, the earth's satellite extends over 3475 km. The Earth is 80 times larger than the Moon, but they are about the same age. The main theory is that at the beginning of its formation, our planet was hit by large object, which tore material into space.
We'll go to the moon again
- NASA plans to create a colony on the lunar surface so that there will always be people there. Work could begin as early as 2019.
In 1950, they planned to detonate a nuclear bomb on the satellite.
- It was a secret project during the Cold War - Project A119. This would show a significant advantage for one of the countries.
Size, mass and orbit of the Moon
The characteristics and parameters of the Moon should be studied. The radius is 1737 km, and the mass is 7.3477 x 10 22 kg, so it is inferior to our planet in everything. However, if compared with the celestial bodies of the Solar System, it is clear that it is quite large in size (in second position after Charon). The density indicator is 3.3464 g/cm 3 (in second place among moons after Io), and gravity is 1.622 m/s 2 (17% of Earth’s).
The eccentricity is 0.0549, and the orbital path covers 356400 – 370400 km (perihelion) and 40400 – 406700 km (aphelion). It takes 27.321582 days to completely circle the planet. In addition, the satellite is in a gravitational block, that is, it always looks at us from one side.
Physical characteristics of the Moon |
| Polar compression | 0,00125 |
|---|---|
| Equatorial | 1738.14 km 0.273 earth |
| Polar radius | 1735.97 km 0.273 earth |
| Average radius | 1737.10 km 0.273 earth |
| Large circumference | 10,917 km |
| Surface area | 3.793 10 7 km² 0.074 earth |
| Volume | 2.1958 10 10 km³ 0.020 earth |
| Weight | 7.3477 10 22 kg 0.0123 earth |
| Average density | 3.3464 g/cm³ |
| Acceleration free falls at the equator |
1.62 m/s² |
| First space speed |
1.68 km/s |
| Second space speed |
2.38 km/s |
| Rotation period | synchronized |
| Axis tilt | 1.5424° |
| Albedo | 0,12 |
| Apparent magnitude | −2,5/−12,9 −12.74 (with full moon) |
Composition and surface of the Moon
The Moon replicates the Earth and also has an inner and outer core, mantle and crust. The core is a solid iron sphere extending over 240 km. An outer core of liquid iron (300 km) is concentrated around it.
You can also find igneous rocks in the mantle, where there is more iron than ours. The crust extends for 50 km. The core covers only 20% of the entire object and contains not only metallic iron, but also small impurities of sulfur and nickel. You can see what the structure of the Moon looks like in the diagram.
Scientists were able to confirm the presence of water on the satellite, most of which is concentrated at the poles in shadowed crater formations and subsurface reservoirs. They think that it appeared due to the contact of the satellite with the solar wind.
Lunar geology diverges from Earth's. The satellite is devoid of a dense atmospheric layer, so there is no weather or wind erosion on it. Small size and low gravity lead to rapid cooling and lack of tectonic activity. You can note a huge number of craters and volcanoes. There are ridges, wrinkles, highlands and depressions everywhere.
The most noticeable contrast is between bright and dark areas. The first ones are called lunar hills, but the dark ones are called seas. The highlands were formed by igneous rocks, represented by feldspar and traces of magnesium, pyroxene, iron, olivine, magnetite and ilmenite.
Basalt rock formed the basis of the seas. Often these areas coincide with lowlands. You can mark channels. They are arcuate and linear. These are lava tubes, cooled and destroyed since volcanic hibernation.
An interesting feature is the lunar domes, created by the ejection of lava into the vents. They have gentle slopes and a diameter of 8-12 km. The wrinkles appeared due to the compression of tectonic plates. Most are found in the seas.
A notable feature of our satellite is impact craters formed when large space rocks fall. Kinetic impact energy forms shock wave, leading to depression, causing a lot of material to be thrown out.
The craters range from small pits to 2500 km and a depth of 13 km (Aitken). The largest appeared in early history, after which they began to decrease. You can find approximately 300,000 depressions with a width of 1 km.
In addition, lunar soil is of interest. It was formed by impacts of asteroids and comets billions of years ago. The stones crumbled into fine dust that covered the entire surface.
The chemical composition of regolith differs depending on the position. If the mountains have a lot of aluminum and silicon dioxide, then the seas can boast of iron and magnesium. Geology was studied not only by telescopic observations, but also by analysis of samples.
Atmosphere of the Moon
The Moon has a weak atmosphere (exosphere), which causes its temperature to fluctuate greatly: from -153°C to 107°C. The analysis shows the presence of helium, neon and argon. The first two are created by solar winds, and the last is the decay of potassium. There is also evidence of frozen water reserves in craters.
Formation of the Moon
There are several theories about the appearance of the earth's satellite. Some people think that it’s all about the Earth’s gravity, which attracted the ready-made satellite. They formed together in the solar accretion disk. Age – 4.4-4.5 billion years.
The main theory is impact. It is believed that a large object (Theia) flew into the proto-Earth 4.5 billion years ago. The torn material began to rotate along our orbital path and formed the Moon. Computer models also confirm this. In addition, the tested samples showed almost identical isotopic compositions to ours.
Connection with the Earth
The Moon revolves around the Earth in 27.3 days (sidereal period), but both objects move around the Sun at the same time, so the satellite spends 29.5 days on one phase for the Earth (known phases of the Moon).
The presence of the Moon has an impact on our planet. First of all, we are talking about tidal effects. We notice this as sea levels rise. The Earth's rotation occurs 27 times faster than the Moon's. Ocean tides are also enhanced by the frictional coupling of water to the earth's rotation through ocean floors, water inertia, and basin oscillation.
Angular momentum accelerates the lunar orbit and lifts the satellite higher over a longer period. Because of this, the distance between us increases, and the earth's rotation slows down. The satellite moves away from us by 38 mm per year.
As a result, we will achieve mutual tidal locking, repeating the situation of Pluto and Charon. But this will take billions of years. So the Sun will most likely become a red giant and swallow us up.
Tides are also observed on the lunar surface with an amplitude of 10 cm for 27 days. Cumulative stress results in moon rays. And they last an hour longer because there is no water to dampen the vibrations.
Let's not forget about such a magnificent event as an eclipse. This happens if the Sun, satellite and our planet line up in a straight line. The lunar one appears if the full Moon appears behind the earth's shadow, and the solar one - the Moon is located between the star and the planet. During a total eclipse, you can see the solar corona.
The lunar orbit is tilted 5° to the Earth's, so eclipses occur at certain moments. The satellite needs to be located near the intersection of orbital planes. The periodicity covers 18 years.
History of lunar observations
What does the history of lunar exploration look like? The satellite is located close and visible in the sky, so prehistoric inhabitants could have followed it. Early examples of recording lunar cycles begin in the 5th century BC. e. This was done by scientists in Babylon, who noted the 18-year cycle.
Anaxagoras of Ancient Greece believed that the Sun and satellite were large-scale spherical rocks, where the Moon reflected sunlight. Aristotle in 350 BC believed that the satellite is the boundary between the spheres of the elements.
The connection between the tides and the Moon was stated by Seleucus in the 2nd century BC. He also thought that the height would depend on the lunar position in relation to the star. The first distance from the Earth and size was obtained by Aristarchus. His data was improved by Ptolemy.
Predict lunar eclipses started by the Chinese in the 4th century BC. They already knew then that the satellite reflected sunlight and was made in a spherical shape. Alhazen said that the sun's rays are not mirrored, but are emitted from each lunar area in all directions.
Until the advent of the telescope, everyone believed that they were seeing a spherical object, as well as a completely smooth one. In 1609, the first sketch by Galileo Galilei appeared, which depicted craters and mountains. This and observations of other objects helped advance Copernicus' heliocentric concept.
The development of telescopes has led to the detailing of surface features. All craters, mountains, valleys and seas were named in honor of scientists, artists and prominent figures. Until the 1870s all craters were considered volcanic formations. But it was only later that Richard Proctor suggested that they might be impact marks.
Exploring the Moon
The space era of lunar exploration has allowed us to take a closer look at our neighbor. Cold War between the USSR and the USA became the reason that all technologies developed rapidly, and the Moon became the main target of research. It all started with spacecraft launches and ended with human missions.
The Soviet Luna program began in 1958, with the first three probes crashing onto the surface. But a year later, the country successfully delivered 15 devices and obtained the first information (information about gravity and images of the surface). The samples were delivered by missions 16, 20 and 24.
Among the models were innovative ones: Luna-17 and Luna-21. But the Soviet program was closed and the probes were limited to just surveying the surface.
NASA started launching probes in the 60s. In 1961-1965. There was a Ranger program that created a map of the lunar landscape. Then in 1966-1968. Rovers landed.
In 1969, a real miracle happened when Apollo 11 astronaut Neil Armstrong took the first step on the satellite and became the first man on the Moon. It was the culmination of the Apollo mission, which had originally aimed for human flight.
There were 13 astronauts on the Apollo 11-17 missions. They managed to extract 380 kg of rock. Also, all participants were engaged in various studies. After this there was a long lull. In 1990, Japan became the third country that managed to install its probe above the lunar orbit.
In 1994, the United States sent a ship to Clementine, who was engaged in the creation of a large-scale topographic map. In 1998, a scout managed to find ice deposits in the craters.
In 2000, many countries became eager to explore the satellite. ESA sent the SMART-1 spacecraft, which for the first time analyzed in detail chemical composition in 2004. China launched the Chang'e program. The first probe arrived in 2007 and remained in orbit for 16 months. The second device was also able to capture the arrival of asteroid 4179 Toutatis (December 2012). Chang'e-3 launched a rover to the surface in 2013.
In 2009, the Japanese Kaguya probe entered orbit, studying geophysics and creating two full-fledged video reviews. Since 2008-2009, the first mission from the Indian ISRO Chandrayaan has been in orbit. They were able to create high-resolution chemical, mineralogical and photogeological maps.
NASA used the LRO spacecraft and the LCROSS satellite in 2009. The internal structure was examined by two additional NASA rovers launched in 2012.
The treaty between the countries states that the satellite remains a common property, so all countries can launch missions there. China is actively preparing a colonization project and is already testing its models on people who are locked in special domes for a long time. America, which also intends to populate the Moon, is not far behind.
Use the resources on our website to view beautiful and high quality photos Moons in high resolution. Useful links will help you find out the maximum known amount of information about the satellite. To understand what the Moon is like today, just go to the appropriate sections. If you can’t buy a telescope or binoculars, then look at the Moon through an online telescope in real time. The image is constantly updated, showing the crater surface. The site also tracks the phases of the moon and its position in orbit. There is a convenient and fascinating 3D model of the satellite, the solar system and all celestial bodies. Below is a map of the lunar surface.
Earth satellites: from artificial to natural
Astronomer Vladimir Surdin about expeditions to the Moon, the Apollo 11 landing site and the equipment of the astronauts:
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