Life without whom would be completely different. Its diameter is 3474 km, and its orbital period is 27.3 days. The moon revolves around the Earth, but it, experiencing the gravity of the satellite, moves in a small orbit, going around common center mass - 1700 km from the earth's surface.
The mass of the Moon is small - only 0.1 of the Earth's, and the average distance from the Earth is about 380,000 km. The speed of the Moon's orbit is 1 km/sec, and it always faces the Earth with one side. Day and night temperatures range from +120°C to -160°C.
There are two types of lunar surface: mountainous, old, with numerous volcanoes, and younger, flat, with smooth lunar seas. The seas are craters from collisions with large celestial objects, later filled with lava.
According to the Giant Impact theory, the impact of a planetary body on the Earth released a certain amount of material from which the Moon was formed.
Some interesting facts
- The Moon is very slowly (4 cm per year), but inevitably moving away from the Earth.
- The moon and the moon look the same size in the sky. This is caused by an amazing coincidence: the earth's satellite is 400 times smaller than the star, but it, in turn, is 400 times further away.
- From lunar surface Only 7% of the light received from the Sun is reflected.
Moon influence
The moon influences both the Earth and its inhabitants. The most important and powerful effect is the ebb and flow. The Earth's satellite lifts with its gravity ocean waters, thereby causing them to ebb from the shores. On the opposite side of the planet, the water in the oceans, on the contrary, is pressed in, causing tides.
Human biorhythms are significantly related to its 28-day cycle. satellite affects organs and circulatory system. The human psyche also experiences pressure from a celestial body. Moreover, the intensity of the influence of the Moon depends on its phases.
Research
We invite you to watch a very interesting lecture about the exploration and flight to the moon:
Due to its accessibility, the earth's satellite has been studied quite fully. The first lunar rover, the first human footprint on the lunar surface are already there. The Moon has no atmosphere, so there are no winds, and a person's footprint will remain unchanged for millions of years. In total, 12 people visited the satellite closest to us. Is it a little or a lot? Only three people have visited the Mariana Trench.
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 occurrence. 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 thanks to a large number iron in the depths of the Moon 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, earth's core There is a solid inner layer and an 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, the studies carried out on the Kola ultra-deep well, found 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 for the 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, near the moon early stage 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 volcanic activity may be present on our satellite. 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.
> > 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 it is not so noticeable due to movement tectonic plates, as well as the atmosphere that burned most spatial violators. 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 more liquid outer shell(500 km). But 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 Earth's natural satellite is the Moon, a non-luminous body that reflects sunlight.
The study of the Moon began in 1959, when the Soviet Luna-2 spacecraft first landed on the Moon, and the Luna-3 spacecraft first took pictures from space. reverse side Moons.
In 1966, Luna 9 landed on the Moon and established a solid soil structure.
The first people to walk on the moon were Americans Neil Armstrong and Edwin Aldrin. This happened on July 21, 1969. Soviet scientists for further study of the Moon preferred to use automatic vehicles - lunar rovers.
General characteristics of the Moon
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The mass of the Moon is 1/81 the mass of the Earth. The position of the Moon in orbit corresponds to one or another phase (Fig. 1).
Rice. 1. Moon phases
Moon phases- various positions relative to the Sun - new moon, first quarter, full moon and last quarter. During a full moon, the illuminated disk of the Moon is visible, since the Sun and Moon are on opposite sides from the Earth. During the new moon, the Moon is on the side of the Sun, so the side of the Moon facing the Earth is not illuminated.
The Moon always faces the Earth with one side.
The line that separates the illuminated part of the Moon from the unlit part is called terminator.
In the first quarter the Moon is visible at angular distance 90" from the Sun, and the sun's rays illuminate only the right half of the Moon facing us. In other phases, the Moon is visible to us in the form of a crescent. Therefore, in order to distinguish the growing Moon from the old one, we must remember: the old Moon resembles the letter “C”, and if the Moon growing, then you can mentally draw in front of the Moon vertical line and you get the letter “R”.
Due to the proximity of the Moon to the Earth and its large mass, they form the Earth-Moon system. The Moon and Earth rotate around their axes in the same direction. The plane of the Moon's orbit is inclined to the plane of the Earth's orbit at an angle of 5°9".
The intersection of the orbits of the Earth and the Moon is called nodes of the lunar orbit.
Sidereal(from Latin sideris - star) month is the period of rotation of the Earth around its axis and the same position of the Moon on the celestial sphere in relation to the stars. It is 27.3 Earth days.
Synodic(from the Greek synod - connection) a month is a period of complete change lunar phases, i.e., the period of the Moon returning to its original position relative to the Moon and the Sun (for example, from new moon to new moon). It averages 29.5 Earth days. Synodic month two days longer than sidereal, since the Earth and Moon rotate around their axes in the same direction.
The gravity on the Moon is 6 times less than the gravity on Earth.
The relief of the Earth's satellite is well studied. The visible dark areas on the surface of the Moon are called “seas” - these are vast waterless lowland plains (the largest is “Oksan Bur”), and the light areas are called “continents” - these are mountainous, elevated areas. The main planetary structures of the lunar surface are ring craters with a diameter of up to 20-30 km and multi-ring circuses with a diameter of 200 to 1000 km.
The origin of ring structures is different: meteorite, volcanic and shock-explosive. In addition, there are cracks, shifts, domes and fault systems on the surface of the Moon.
Research spacecraft"Luna-16", "Luna-20", "Luna-24" showed that the surface clastic rocks of the Moon are similar to terrestrial igneous rocks - basalts.
The meaning of the Moon in the life of the Earth
Although the mass of the Moon is 27 million times less than the mass of the Sun, it is 374 times closer to the Earth and has a strong influence on the planet, causing rising tides in some places and low tides in others. This happens every 12 hours 25 minutes, as the Moon does full turn around the Earth in 24 hours 50 minutes.
Due to the gravitational influence of the Moon and the Sun on the Earth, ebb and flow(Fig. 2).
Rice. 2. Scheme of the occurrence of ebbs and flows on Earth
The most distinct and important in their consequences are tidal phenomena in the wave shell. They represent periodic rises and falls in the level of oceans and seas, caused by the gravitational forces of the Moon and the Sun (2.2 times less than the lunar one).
In the atmosphere, tidal phenomena manifest themselves in semidiurnal changes atmospheric pressure, and in earth's crust- in the deformation of the solid matter of the Earth.
On Earth, there are 2 high tides at the point closest and farthest from the Moon and 2 low tides at points located at an angular distance of 90° from the Moon-Earth line. Highlight cygisian tides, which occur on new and full moons and quadrature- in the first and last quarter.
IN open ocean tidal effects are small. Water level fluctuations reach 0.5-1 m. In the inland seas (Black, Baltic, etc.) they are almost not felt. However, depending on the latitude and the contours of the continental coastlines (especially in narrow bays), water during high tides can rise up to 18 m (Bay of Fundy in Atlantic Ocean off the coast North America), 13 m on the western coast of the Sea of Okhotsk. In this case, tidal currents are formed.
The main significance of tidal waves is that, moving from east to west following visible movement Moons, they slow down axial rotation Earth and lengthen the day, change the figure of the Earth by reducing polar compression, cause pulsation of the Earth's shells, vertical displacements of the earth's surface, semidiurnal changes in atmospheric pressure, change the conditions of organic life in the coastal parts of the World Ocean and, finally, influence economic activity coastal countries. Sea vessels can only enter a number of ports at high tide.
After a certain period of time on Earth they repeat solar and lunar eclipses. They can be seen when the Sun, Earth and Moon are on the same line.
Eclipse- an astronomical situation in which one celestial body blocks the light from another celestial body.
Solar eclipse occurs when the Moon comes between the observer and the Sun and blocks it. Since the Moon before an eclipse faces us with its unlit side, there is always a new moon before an eclipse, i.e. the Moon is not visible. It seems that the Sun is covered by a black disk; an observer from Earth sees this phenomenon as a solar eclipse (Fig. 3).
Rice. 3. Solar eclipse (the relative sizes of the bodies and the distances between them are relative)
A lunar eclipse occurs when the Moon, while aligned with the Sun and Earth, falls into the cone-shaped shadow cast by the Earth. The diameter of the Earth's shadow spot is equal to the minimum distance of the Moon from the Earth - 363,000 km, which is about 2.5 times the diameter of the Moon, so the Moon can be completely obscured (see Fig. 3).
Lunar rhythms are repeated changes in intensity and character biological processes. There are lunar-monthly (29.4 days) and lunar-diurnal (24.8 hours) rhythms. Many animals and plants reproduce in a certain phase lunar cycle. Lunar rhythms are characteristic of many marine animals and plants coastal zone. Thus, people have noticed changes in their well-being depending on the phases of the lunar cycle.
Photo: Moon – natural satellite Earth and the unique alien world visited by humanity.
Moon
Characteristics of the Moon
The Moon revolves around the Earth in an orbit whose semi-major axis is 383,000 km (ellipticity 0.055). The plane of the lunar orbit is inclined to the plane of the ecliptic at an angle of 5°09. Rotation period equals 27 days 7 hours 43 minutes. This is the sidereal or sidereal period. The synodic period - the period of change of lunar phases - is equal to 29 days 12 hours 44 minutes. The period of rotation of the Moon around its axis is equal to the sidereal period. Because the time of one revolution The Moon around the Earth is exactly equal to the time of one revolution around its axis, the Moon always facing the Earth the same side. The Moon is the most visible object in the sky after Sun. Maximum magnitude equal to – 12.7m.
Weight Earth's satellite is 7.3476*1022 kg (81.3 times less than the mass of the Earth), average density p = 3.35 g/cm3, equatorial radius – 1,737 km. There is almost no contraction from the poles. Acceleration free fall on the surface is g = 1.63 m/s2. The Moon's gravity could not retain its atmosphere, if it ever had one.
Internal structure
Density The density of the Moon is comparable to the density of the Earth's mantle. Therefore, the Moon either has no or very insignificant iron core. Internal structure The Moon was studied using seismic data transmitted to Earth by devices of the Apollo space expeditions. The thickness of the Moon's crust is 60–100 km.
Photo: Moon - internal structure
Thickness upper mantle 400 km. In it, seismic velocities depend on depth and decrease depending on distance. Thickness middle mantle about 600 km. In the middle mantle, seismic velocities are constant. Lower mantle located below 1100 km. Core The Moon, starting at a depth of 1500 km, is probably liquid. It contains virtually no iron. As a result, the Moon has a very weak magnetic field, not exceeding one ten-thousandth of the Earth's magnetic field. Local magnetic anomalies have been recorded.
Atmosphere
There is virtually no atmosphere on the Moon. This explains the sudden temperature changes several hundred degrees. IN daytime the temperature on the surface reaches 130 C, and at night it drops to –170 C. At the same time, at a depth of 1 m, the temperature is almost always constant. Sky above the moon is always black, because for education blue color sky is necessary air, which is missing there. There is no weather there, and the winds do not blow. In addition, the moon reigns complete silence.
Photo: the surface of the Moon and its atmosphere
Visible part
Only visible from Earth visible part of the Moon. But this is not 50% of the surface, but a little more. The Moon revolves around the Earth ellipse, near perigee the Moon moves faster, and near apogee it moves slower. But the Moon rotates uniformly around its axis. As a result, an oscillation in longitude is formed. Its probable maximum value is 7°54. Due to libration, we have a chance to observe from Earth except visible side The moon also has adjacent narrow strips of territory on its reverse side. In total, 59% of the lunar surface can be seen from Earth.
Moon in early times
There is an assumption that in early times throughout its history, the Moon revolved around its axis faster and, therefore, turned towards the Earth various parts its surface. But due to the proximity of the massive Earth, impressive tidal waves. The process of deceleration of the Moon lasted until it was invariably turned to us with only one side.
