Why is the moon a satellite of the earth? Our natural satellite is the moon. Methods, techniques, forms
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Lesson summary using information technologies(ICT)
Item: the world.
UMK: N.Ya. Dmitrieva, A.N. Kazakov, developmental training “L.V. Zankov System”
Class: 2
Lesson type: familiarization with new material.
Lesson topic: The Moon is the Earth's satellite.
Duration: 40 min.
Annotation: II quarter, studied module “Space”, lesson 5.
Methods, techniques, forms:
– verbal (conversation), playful;
– visual (multimedia presentation;);
– practical;
– method of self-control;
– problematic, organization of search and research work;
A combination of frontal, individual, group and pair work;
The lesson on the surrounding world was developed in accordance with the requirements of the Federal State Educational Standard of NEO.
Target: expand students' knowledge about the Moon.
Tasks:
introduce the Earth's satellite - the Moon, with its movement around the Earth, size and distance from the Earth;
explain why the visible shape of the Moon changes throughout the month.
Developmental tasks:
develop spatial imagination, cognitive interest, outlook, creativity;
develop the ability to work with a globe and educational text;
develop self-control and control skills, skills practical work in groups;
develop cognitive activity children, the ability to observe, compare, generalize and draw conclusions.
Educational tasks:
contribute to the formation of the student’s personality, support the needs and motives to learn “new things”;
instill respect for each other;
to form an emotionally positive attitude towards the subject, showing the connection of the subjects being studied with life.
Value guidelines: inquisitive, actively and interestedly exploring the world.
Planned results:
Personal UUD:
the formation of a holistic, socially oriented view of the world in its limited unity;
to form motivation for learning and purposeful cognitive activity;
perceive classmates as members of your team (group);
contribute to the work to achieve common results;
be tolerant of other people’s and own mistakes, other opinions and be willing to discuss them.
Metasubject UUD.
Regulatory UUD:
together with the teacher, discover and formulate an educational problem;
after preliminary discussion, independently formulate the topic of the lesson and the purpose of the lesson;
predict upcoming work: determining the purpose of educational activities, choosing a topic, drawing up a plan;
evaluate learning activities in accordance with the task;
compare your actions with the goal, learn to evaluate the results of educational activities;
perform self-checks against the standard and adjust your activities.
Cognitive UUD:
navigate your knowledge system;
extract and process information to discover new knowledge;
extract information presented in different forms(test, text, illustration);
process the information received: draw conclusions as a result collaboration the whole class, group, pair.
Communicative UUD:
convey your position to others: express your point of view and try to substantiate it by giving arguments;
express your thoughts in speech and convey your position to others;
listen to others, try to accept a different point of view, be willing to change your point of view;
jointly agree on the rules of communication and behavior in the group and follow them;
consciously choose a criterion for qualitative assessment of the group’s work.
Subject UUD:
be able to explain the meaning of “The Moon is a satellite of the Earth”;
to Work with ready-made models(globe);
expand knowledge about the Moon.
Training technologies: technology of developmental education, technology of activity approach, technology problem-based learning, health-saving, technology for assessing educational achievements.
Equipment: computer, multimedia lesson presentation, Handout for group work: evaluation signal cards, masks for a skit (moon phases), the vocabulary word “crater”.
During the classes
I .Motivation for learning activities(children in chorus) (slide 1)
The bell rang
The lesson begins.
To become nature's friend
Find out all her secrets,
Solve all the riddles
We learn to observe.
Let's develop mindfulness together,
And our curiosity will help us find out everything.
Hello guys, look at each other, smile and sit down. Now we have a lesson about the world around us.
I I . Updating knowledge
Before you start studying new topic, we will take a test, thereby checking how well you have mastered the topic of the last lesson.(slide 2 - 7)
Test (System for control and monitoring of knowledge quality) PRoClass
The planets of the solar system are being studied...
A) geographers;
B) chemists;
B) astronomers;
D) physicists.
Planets revolve around the Sun. Their...
A) 7;
B) 9;
AT 11.
Pluto is...
A) the largest planet in the solar system;
B) the smallest planet in the solar system;
C) the planet closest to the Sun in the Solar System.
The planets are located relative to the Sun as follows:
A) Venus, Earth, Mars, Mercury, Neptune, Pluto, Saturn, Uranus, Jupiter;
B) Mercury, Venus, Earth, Mars, Neptune, Pluto, Saturn, Jupiter, Uranus;
C) Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.
What is Earth?
A) star;
B) planet;
B) a flaming ball.
III . Formulating a lesson topic, setting a goal
I have prepared a small crossword puzzle for you. Let's guess it and see what keyword we come up with. (slide 8)
The star around which the Earth revolves?
What is the most distant planet from the Sun?
A celestial body orbiting the Sun?
A celestial body that itself glows?
So, what was the keyword? (Moon)
So what are we going to talk about today? (about the Moon)
Have you seen the moon?
What do you know about her?
Do you know everything about her?
Would you like to know more? (Yes)
What do you think is the topic of our lesson? ("The Moon is the Earth's satellite") (slide 9)
Let's see what we should learn about her during this lesson? (slide 10)
1. The Moon is a satellite of the Earth.
Surface of the Moon.
Lunar phases.
Human exploration of the Moon.
To find out all this, we will go on an extraordinary journey to the Moon. You will be real researchers, astronomers. Will be based on scientific facts draw conclusions.
So, are you ready to go on an extraordinary journey?
Fasten seat belts! Attention! Takeoff!
I V. Discovery of new knowledge.
Here you and I are in place. Let's start looking for answers to our questions?
1. The Moon is a satellite of the Earth. (slide 11)
Guys, in front of you is our planet Earth and the Moon. What can you say about them?
What is the size of the Moon compared to the size of the Earth?
The Moon turns out to be 4 times smaller than the Earth.
What is the distance from the Earth to the Moon?
The distance to the moon is approximately 400 thousand km. This is the closest cosmic body to Earth.
It turns out that the Earth and the Moon, they are like 2 brothers, are always inseparable. The Moon moves around the Earth, and together with the Earth around the Sun. That's why the Moon is called the Earth's satellite.
To better imagine all this, let’s briefly turn ourselves into the Sun, planet Earth and the Moon. We will try to show the movement of the Earth around the Sun, and the Moon around the Earth. (Children demonstrate how the Sun, Earth and Moon move. Student - The Sun rotates around itself. Student - Earth - around itself and very slowly around the Sun. Student - The Moon rotates around itself and around the Earth.)
Here we have clearly seen the movement of the Earth's satellite, the Moon.
Well done, sit down.
Now open the textbooks p. 65 and read the first paragraph. Let's find out what the authors of the textbook offer us? (slide 12)
So, why is the Moon called the Earth's satellite? (children's answers)
2. Surface of the Moon.(slide 13)
What do you see in the image?
Look at the surface of the Moon and tell me what it is like?
Look at the photo of the Moon and listen to the poem by Gianni Rodari, which your classmate will tell us... (one student says). Think about what was called the lunar seas. (Most likely, these are mountains and depressions on the surface of the Moon.)
By the lunar sea
Special secret -
It doesn't look like the sea.
There is not a drop of water in this sea,
And there are no fish either.
In the waves of it
Impossible to dive
You can't splash around in it,
You can't drown.
Swim in that sea
Convenient only for those
Who swim
He still can’t do it at all!
What does it say about the surface of the Moon? (the surface of the Moon is rocky and very uneven. Mountains alternate with plains covered with dust. There are many depressions on the Moon that were formed from meteorite impacts on its surface).
Guys, these depressions are called craters, or in another way they are called “lunar seas”.
Let's repeat this word in chorus - crater (in unison).
People even gave names to these seas: Sea of Tranquility, Sea of Rains, Ocean of Storms.
So what are “lunar seas”? (craters formed due to the fall of meteorites - stones fallen from space).
Fizminutka
Don't yawn around, there will be a right turn.
You are an astronaut today! One - clap, two - clap,
Let's start training, turn around one more time!
To become strong and agile. One two three four,
Let's put our arms to the sides, shoulders higher, arms wider.
Let's get the left one with the right one, lower our hands down
And then vice versa - And sit down at your desk again!
3. Moon phases
- Now, guys, watch the fairy tale that your classmates and I have prepared for you. It's called "Why doesn't the month have a dress?" And think about why they called her that? (dramatization of a fairy tale by two students)Annex 1
What secret does this tale reveal? (slide 14)
Why doesn't the month have a dress? (The moon is different)
Do you know what determines the different appearance of the Moon?
Work in pairs (using document and cameras)
- Let's remember the rules of working in pairs and groups. Appendix 2
- Compare your sketches of the Moon with those in the textbook.
Why do we see the Moon so different from Earth? (Messages from children)
Different view The appearance of the Moon depends on how it is illuminated by the Sun, which is invisible to us at night. The appearance of the Moon changes throughout the month because it occupies different position relative to the Sun and Earth. Even in ancient times, people noticed that the Moon changes its shape all the time. Sometimes it looks like a round plate, sometimes like a sickle, which was called the month. There is an explanation for all this. The sun is a flaming ball. It emits light. And the Moon does not emit light; it is like a mirror, reflecting the light of the Sun. The sun's rays illuminate it from only one side. Only this illuminated side of the Moon is visible from Earth. As the Moon moves around the Earth, the Sun illuminates it differently. Depending on what part of the Moon is illuminated, we see it in the sky – either in its entirety, then in half, or as a narrow crescent. If you observe the Moon, you will notice that the crescent of the “young”, “growing” Moon is different from the “aging” Moon. To do this, you need to connect the tips of the horns with a straight line segment and extend this line down a little. We will get the letter “P”, i.e. the first letter of the word "growing". So we drew a young Moon. And the “aging” sickle itself speaks about this, because it looks like the letter “C” - the first letter of the word “aging”.
Human exploration of the Moon.(slide 15)
Guys, do you think people dreamed of visiting the Moon? (Messages from children)
People have long dreamed of visiting the Moon. The real assault on the Moon begins in 1959. In 1966, the Luna 9 station landed on the moon and transmitted a television image of the lunar landscape. In 1970, the Luna-16 station drilled and delivered lunar soil to Earth. Other countries also studied the Moon.
And now you will learn about who managed to visit the Moon. (Messages from children)
In 1969, American astronauts Neil Armstrong and Edwin Aldrin walked on the moon. They even managed to ride on a lunar rover. In 1970, the first domestic self-propelled vehicle “Lunokhod - 1” began its movement on the surface of the Moon. Many craters on the Moon are caused by falling meteorites, because... The Moon does not have an atmosphere, unlike the Earth. Due to the lack of atmosphere on the surface of the Moon, sharp temperature fluctuations occur. On a sunlit surface it rises to +130 degrees, and at night it drops to -160 degrees.
- What were the names of the American astronauts who walked on the moon? ( Neil Armstrong, Edwin Aldrin)
What did astronomers manage to find out as a result of studying the Moon? (Scientists have proven that there is no air, water, and therefore no animals and plants on the Moon.)
Have we received answers to previously unknown questions?
Now close your eyes and imagine that you and I are flying back to Earth. Happy landing to you guys!
V. Consolidation of the studied material(slide 16)
So you and I have learned a lot about the Earth’s satellite, the Moon. Now let’s check how well you remember everything.
Group work
Place statements on the tables using the words given to you. But keep in mind that not all words will be useful to you.
I group
II group
(
III group
Read the statements you received.
One of the groups came across the surname Gagarin. Who can tell me who this is? (the first person to fly into space).
Give his full name. (Yuri Alekseyevich Gagarin)
Or maybe someone can tell me the year when Yuri Gagarin made his flight? ( April 12, 1961)
Well done boys!
VI. Reflection on learning activities in the classroom.
- The bell will ring soon
Let's sum it up quickly.
What new did you learn in the lesson? (about the fact that the Moon is a satellite of the Earth, about the surface of the Moon, about the phases, about people who conquered the moon)
Self-assessment of work
I suggest that you evaluate your work in class: (on everyone’s table there are stars of three colors)
Red star- the lesson was easy and interesting.
Yellow star- experienced difficulties.
Brown star- the lesson was boring, difficult, I didn’t understand anything.
Home rear Prepare a message about the Moon on behalf of an astronaut or astronomer scientist.
Bibliography:
Dmitrieva N.Ya., Kazakov A.N. The world: Textbook for grade 2: In 2 hours – 8th edition. – Samara: Publishing House “Educational Literature”: Publishing House “Fedorov”, 2012.
Dmitrieva N.Ya., Kazakov A.N. Workbook on the surrounding world for grade 2 - Samara: Publishing House "Educational Literature": Publishing House "Fedorov", 2013.
Gulueva T.S. The world around us, grade 2. Guidelines to the textbook Dmitrieva N.Ya., Kazakov A.N. The world around us, grade 2. – Volgograd: Teacher, 2009. – 281 p.
Annex 1
Fairy tale “Why the month doesn’t have a dress”
Crescent dropped in to see Tailor,
Not to the heavenly, but to the earthly.
-Sew it for me, master, elegant dress,
I will walk across the sky on holiday!
The Tailor took the measurements from the Crescent.
Invites him to a fitting.
But in just a few days
The month became twice as full.
Both his shoulders and chest are tight
Thus the Heavenly Moon has recovered!
Tailor almost cries with frustration:
-What kind of demon played a trick on me!
Your Grace has gained a little weight
Or the matter has shrunk from washing, -
To be honest, I don't understand...
OK! I'll take a new fitting.
Day after day goes by,
Tailor doesn't waste a minute.
Well, the Moon is a night reveler
Became meanwhile full moon.
He tries on a tight dress
And, sighing, mutters curses:
-Sinner, swindler, villain!
I would be ashamed of good people.
For the last three days and three nights
The dress has become tighter and shorter!
Tailor did not answer anything,
Why can Tailor argue with Luna?
He took the customer’s measurements again:
The dress will be ready for the holiday.
The seams of the dress were ripped apart by the tailor,
The chest was expanded and the hem was added.
There's still a little work left to do,
And the Moon is knocking on the window.
Yes, not a Month, but a thin Sickle
At this time he was doing damage,
Not the Moon, but just half:
Only horns yes round back.
Tailor shook all over with anger:
-No, stop joking with me!
I tried to please you foolishly.
Every day, you changed your figure.
Then you became round like a pancake.
That's as thin as this arshin.
Sewing a dress for you is a waste of time,
Better stay without a dress!
Appendix 2
Rules for working in pairs
Both should work.
One speaks, the other listens.
If you don't understand, ask again.
Group rules
There must be a person in charge in the group.
If you don't understand, ask again.
One speaks, others listen.
Express your disagreement politely.
Everyone must work for the common result.
Appendix 3
Cards with statements for group work.
I group
Mars, Sun, Moon, artificial, natural, satellite of the Earth, Pluto.
("Moon - natural satellite Earth")
II group
The first, people, animals, Armstrong, Gagarin, who conquered, Aldrin, the Moon. ( The first people to conquer the moon - Armstrong and Aldrin")
III group
Craters formed by comets, from impacts, depressions, these are meteorites. (Craters are depressions formed by meteorite impacts.)
Appendix 4
Creative report with photographic materials
It is also the first (and as of 2010, the only) extraterrestrial object of natural origin visited by humans. The average distance between the centers of the Earth and the Moon is 384,467 km.
The lunar landscape is peculiar and unique. The moon is all covered in craters different sizes- from hundreds of kilometers to a couple of millimeters. For a long time Scientists could not look at the far side of the Moon; this became possible with the development of technology.
Scientists have now created very detailed maps of both surfaces of the Moon. Detailed lunar maps are drawn up in order to prepare in the near future for landing a man on the Moon, the successful location of lunar bases, telescopes, transport, searching for minerals, etc.
Name
The word moon goes back to the Proto-Slavic form *luna< и.-е. *louksnā́ «светлая» (ж. р. прилагательного *louksnós), к этой же индоевропейской форме восходит и латинское слово lūna «луна». Греки называли спутник Земли Селеной (греч. Σελήνη), древние египтяне - Ях (Иях). На всех тюркских (кроме чувашского) языках луна будет «ай».
Movement of the Moon
To a first approximation, we can assume that the Moon moves in an elliptical orbit with an eccentricity of 0.0549 and a semimajor axis of 384,399 km. The actual motion of the Moon is quite complex; many factors must be taken into account when calculating it, for example, the oblateness of the Earth and the strong influence of the Sun, which attracts the Moon 2.2 times stronger than the Earth. More precisely, the movement of the Moon around the Earth can be represented as a combination of several movements:
Rotation around in an elliptical orbit with a period of 27.32 days;
precession (plane rotation) of the lunar orbit with a period of 18.6 years (see also saros);
rotation of the major axis of the lunar orbit (apse line) with a period of 8.8 years;
periodic change in the inclination of the lunar orbit relative to the ecliptic from 4°59′ to 5°19′;
periodic change in the size of the lunar orbit: perigee from 356.41 Mm to 369.96 Mm, apogee from 404.18 Mm to 406.74 Mm;
the gradual removal of the Moon from the Earth (about 4 cm per year) so that its orbit is a slowly unwinding spiral. This is confirmed by measurements carried out over 25 years.
The force that causes the Moon to move away from the Earth is the transfer of angular momentum from the Earth to the Moon through tidal interaction.
The gravitational interaction between the Moon and the Earth is not constant; as the distance increases, the strength of the interaction decreases. This leads to the fact that with increasing distance the speed of the Moon's retreat decreases.
The period of revolution of the Moon around the Earth relative to the stars is 27.32166 days, this is the so-called sidereal month.
The full Moon reflects only 7% of the sunlight falling on it. After periods of intense solar activity separate places The lunar surface may glow faintly due to luminescence. Since the Moon does not glow itself, but only reflects sunlight, only the part of the lunar surface illuminated by the Sun is visible from Earth.
The Moon orbits the Earth, and thereby the angle between the Earth, Moon and Sun changes; we observe this phenomenon as a cycle of lunar phases. The period of time between successive new moons is 29.5 days (709 hours) and is called the synodic month.
The fact that the duration of the synodic month is longer than the sidereal month is explained by the movement of the Earth around the Sun: when the Moon makes a full revolution around the Earth relative to the stars, by this time the Earth has already passed 1/13 of its orbit, and for the Moon to again be between the Earth and the Sun, she needs about two extra days.
Although the Moon rotates around its axis, it always faces the Earth with the same side, that is, the rotation of the Moon around the Earth and around its own axis is synchronized. This synchronization is caused by the friction of the tides that the Earth produced in the Moon's shell. According to the laws of mechanics, the Moon is oriented in the Earth's gravitational field so that the semimajor axis of the lunar ellipsoid is directed toward the Earth.
There is a difference between the rotation of the Moon around its own axis and its revolution around the Earth: the Moon rotates around the Earth according to Kepler’s law (unevenly, that is, faster near perigee, slower near apogee). However, the rotation of the satellite around its own axis is uniform. It is thanks to this that it is possible to look at the far side of the Moon from the west or from the east. This phenomenon of oscillation is called optical libration along longitude.
Due to the tilt of the Moon’s axis relative to the Earth’s plane, it is possible to look at the far side from the north or south. This is also optical libration, but in latitude. These librations together make it possible to observe about 59% of the lunar surface. This phenomenon of optical libration was discovered by Galileo Galilei in 1635, when he was convicted by the Inquisition.
There is also physical libration, caused by the oscillation of the satellite around the equilibrium position due to the displaced center of gravity, as well as under the influence of tidal forces from the Earth. These fluctuations constitute the so-called. physical libration, which is 0.02° in longitude with a period of 1 year and 0.04° in latitude with a period of 6 years.
Conditions on the Moon's surface
The Moon has virtually no atmosphere. The gas content at the surface at night does not exceed 200,000 particles/cm³ and increases by two orders of magnitude during the day due to soil degassing. This concentration of gases is equivalent to a deep vacuum, so during the day its surface heats up to +120 °C, but at night or even in the shade it cools down to −160 °C.
The sky on the Moon is always black, even during the day. The huge disk of the Earth looks 3.67 times larger from the Moon than the Moon from Earth and hangs almost motionless in the sky. The Earth's phases as seen from the Moon are exactly opposite lunar phases on the ground. Illumination by reflected light on Earth is approximately 50 times stronger than illumination by moonlight on Earth.
The surface of the Moon is covered with so-called regolith - a mixture of fine dust and rocky debris formed as a result of meteoroid collisions with the lunar surface. The thickness of the regolith layer varies from fractions of a meter to tens of meters.
Ebbs and flows
The gravitational forces between the Earth and the Moon cause some interesting effects. The most famous of them is sea tides. If we looked at the Earth from the side, we would see two bulges located on opposite sides of the planet.
Moreover, one point is on the side closest to the Moon, and the other is on the opposite side of the Earth, farthest from the Moon. In the world's oceans this effect is much more pronounced than in the solid crust, so the convexity of the water is greater. Tidal amplitude (difference between high and low tide levels) on open spaces ocean is small and amounts to 30-40 cm.
However, near the coast, due to the impact of a tidal wave on a hard bottom, a tidal wave increases in height in the same way as ordinary wind waves of the surf. Taking into account the direction of rotation around the Earth, it is possible to create a picture of a tidal wave following the ocean. The eastern coasts of continents are more susceptible to strong tides. The maximum tidal wave amplitude on Earth is observed in the Bay of Fundy in Canada and is 18 meters.
The two highest tides are formed due to the fact that the gravitational field of the Moon is quite heterogeneous over the size of the Earth. If we decompose the vector of the gravitational field directed towards the Moon into 2 components - parallel to the Earth-Moon axis and perpendicular to it, then we can see that the cause of tides is the perpendicular component. Parallel component along dimensions
The Earth changes little, but the perpendicular component changes sign! It is maximum in magnitude and directed oppositely on the lateral sides of the Earth, which are as far removed from the Earth-Moon axis as possible. This is the “gravity force of the tide,” which creates a flow of ocean water towards areas located on the Moon-Earth axis on both sides of the globe.
The inhomogeneity of the Moon's field near the Earth is much higher than the inhomogeneity of the Sun's field. Although the gravity of the Sun is much greater, its field over the size of the Earth is almost uniform, since the distance to the Sun is 400 times greater than the distance to the Moon. Therefore, tides arise mainly due to the influence of the Moon. The tidal force of the Sun is on average 2.17 times less.
Geology of the Moon
Due to its size and composition, the Moon is sometimes classified as a planet. terrestrial group along with Mercury, Venus, Earth and Mars. Therefore, studying geological structure Moon, you can learn a lot about the structure and development of the Earth.
The thickness of the Moon's crust averages 68 km, varying from 0 km under the lunar Sea of Crisis to 107 km in the northern part of the Korolev crater on the far side. Beneath the crust is the mantle and possibly a small core of iron sulfide (with a radius of approximately 340 km and a mass of 2% of the Moon's mass). It is curious that the center of mass of the Moon is located approximately 2 km from the geometric center towards the Earth. On the side facing the Earth, the crust is thinner.
Measurements of the speed of the Lunar Orbiter satellites made it possible to create a gravitational map of the Moon. With its help, unique lunar objects were discovered, called mascons (from the English mass concentration) - these are masses of matter of increased density.
The moon has no magnetic field, although some of rocks its surface exhibits residual magnetism, which indicates the possibility of the existence of the Moon’s magnetic field on early stages development.
Having neither an atmosphere nor a magnetic field, the surface of the Moon is directly affected by solar wind. Over the course of 4 billion years, hydrogen ions from the solar wind were introduced into the lunar regolith.
Thus, regolith samples returned by the Apollo missions have proven to be very valuable for solar wind research. This lunar hydrogen could also one day be used as rocket fuel.
Surface of the Moon
The surface of the Moon can be divided into two types: very old mountainous terrain (lunar continent) and relatively smooth and younger lunar maria. Lunar maria, which make up approximately 16% of the lunar surface, are huge craters created by collisions with celestial bodies that were later flooded with liquid lava. B
Most of the surface is covered with regolith. The lunar maria, under which denser, heavier rocks have been discovered by lunar satellites, are concentrated on the side facing the Earth due to the influence of the gravitational moment during the formation of the Moon.
Most of the craters on the side facing us are named famous people in the history of science, such as Tycho Brahe, Copernicus and Ptolemy. The relief details on the reverse side have more modern names like Apollo, Gagarin and Korolev.
On the far side of the Moon there is a huge depression (pool) with a diameter of 2250 km and a depth of 12 km - this is the largest basin in the Solar System that appeared as a result of the collision. The Eastern Sea in the western part visible side(visible from Earth) is an excellent example of a multi-ring crater.
Also, minor details of the lunar relief are distinguished - domes, ridges, rilles (from the German Rille - furrow, trench) - narrow winding valley-like depressions of the relief.
Caves
The Japanese Kaguya probe discovered a hole in the surface of the Moon, located near the volcanic plateau of the Hills of Marius, presumably leading to a tunnel below the surface. The diameter of the hole is about 65 meters, and the depth is presumably 80 meters.
Scientists believe that such tunnels are formed by the solidification of flows of molten rock, where lava has frozen in the center. These processes occurred during the period of volcanic activity on the Moon. This theory is confirmed by the presence of winding grooves on the surface of the satellite.
Such tunnels can serve for colonization, thanks to protection from solar radiation and the enclosed space in which it is easier to maintain life support conditions.
Similar holes exist on Mars.
Origin of the Moon
Before scientists received samples lunar soil, they knew nothing about when and how the Moon was formed. There were three fundamentally different theories:
The Moon and Earth formed at the same time from a cloud of gas and dust;
The Moon was formed by the collision of the Earth with another object;
The Moon formed elsewhere and was subsequently captured by the Earth.
However new information, obtained by detailed study samples from the Moon led to the creation of the Giant Impact theory: 4.57 billion years ago, the protoplanet Earth (Gaia) collided with the protoplanet Theia. The blow did not land in the center, but at an angle (almost tangentially). As a result, most of the substance of the impacted object and part of the substance of the earth's mantle were thrown into low-Earth orbit.
The Moon is a natural satellite of our planet. Its influence is so great that astronomers often talk about the Earth-Moon conjunction not as a planet and a satellite, but as double planet. Disputes about its origin still rage. Let's try to figure them out.
What is this strange “planet”?
The Moon influences almost every aspect of life on Earth, and the history of human civilization was no exception. Mammoth hunters also counted days using the phases of the moon. For the first civilizations, the Earth's satellite was a deity who controlled the most important thing - the agricultural cycle. In most ancient civilizations, the Moon was considered a powerful goddess to whom temples were built and sacrifices (sometimes human) were made. Eclipses of the Moon caused horror - the deity covered his face in anger, disasters were coming! In the Middle Ages, the Moon was considered the habitat of angels; during the Enlightenment, people indulged in dreams of a race of Selenites living on the night luminary. Scientific progress quickly destroyed these naive ideas. The Moon turned out to be a small planet, lifeless and unattractive (from a human point of view). But it also turned out that the influence of our satellite on the processes occurring on Earth is very great - probably, without the Moon, the biosphere could not exist on Earth, and our planet would be similar to Mars or Venus. After all, it is the presence of the Moon that determines the most important climatic parameter - the inclination of the planet’s rotation axis relative to the plane of its orbit, which determines the nature of the change of seasons.
From the laws of celestial mechanics it is known that the inclination of the axis of rotation of planets is subject to fluctuations, an example of which is our neighbor Mars. As calculations performed by astronomers show, the angle between the equator of Mars and the plane of its orbit changed significantly. But the surface of the Red Planet contains numerous signs of a different past - channels, channels, sedimentary rocks (traces of ancient seas!). In the distant past, the planet's climate was warmer, and liquid water, and possibly life, existed on its surface. But some kind of catastrophe occurred, and Mars turned into an icy desert. Research shows that the most probable cause The “freezing” of Mars was a change in the angle of inclination of the Martian axis. For the Earth, even an insignificant change in the angle of inclination of the axis to the ecliptic plane (by an amount of the order of a degree) can provide glacial period. Meanwhile, Mars was rotating by tens of degrees, so grandiose climate disasters on it were inevitable. But on Earth, the angle of inclination of the axis relative to the orbital plane varied by no more than one or two degrees, which ensured amazing (by the standards of other planets) climate stability. A natural question arises - what is the reason for the unique stability of our planet?
How the Moon helps us
Most scientists believe that stability earth's rotation(and, accordingly, the climate) we must thank the Moon - it is thanks to it that chaotic fluctuations in the angle of inclination do not threaten the Earth. The hypothetical absence of a large satellite near the Earth would create conditions for very strong fluctuations in the angle between the equator and the orbit, which would make the climate on Earth uninhabitable.
The beneficial role of the Moon was not limited to this, contributing to the emergence of life: it caused tides that contributed to the aeration of the seas. Perhaps even life itself first began in the intertidal zone! The movement of the Moon across the sky affects the life cycles of many organisms - a shining example serve as horseshoe crabs (marine arthropods distantly related to crayfish and crabs), which spawn only at a certain phase of the moon.
It undoubtedly influenced the history of mankind. As an ideal celestial chronometer, the Earth's satellite significantly accelerated the appearance of the first calendars. Observations of the Moon (the closest celestial body) played a huge role in the development of astronomy. From them, ancient scientists concluded that the planets were spherical, and the movement of the Moon and its connection with sea tides made it possible in the 17th century to formulate the laws of universal gravitation.
Later, observations of the Moon contributed to the development of planetary science - after all, no other planet (except the Earth) has been studied in such detail! However, as knowledge about the Moon accumulated, a number of questions arose. The biggest mystery remained the origin of the Moon - many hypotheses for the origin of the night luminary were put forward, but none of them could explain all the facts. What are the main features of our satellite that caused such difficulties for scientists?
We list the main ones:
- the average density of the Moon is much less medium density the Earth, since the Moon has a very small core (if the Earth has about 30% of the mass of the planet, then the Moon has no more than 2-3%);
- on the Moon the content is increased heavy elements(thorium, uranium, titanium);
- but the ratio of oxygen isotopes in the earth’s and lunar crust is almost the same (but it varies greatly among different planets and meteorites from different parts of the solar system);
- the lunar crust is much thicker than the earth’s, which presumably indicates that all the matter composing it was once molten (but the Earth is believed to have never been completely molten);
- finally, the plane of the Moon’s orbit does not coincide with the equatorial plane of the Earth.
Among the numerous assumptions about the mechanism of origin of our satellite, three hypotheses in different time gained the greatest popularity among scientists. Let's talk about them too.
Hypotheses for the origin of the Moon
According to one of these hypotheses, our companion was once an “independent” small planet in the solar system, revolving around the Sun. However, at some point, the free Moon came too close to the Earth - and the force of gravity captured it and transferred it to a new orbit, where the Moon was destined to revolve around our planet as a satellite.
Alas, calculations showed that this hypothesis cannot explain the features of the lunar orbit, and the similarity of the elements of the earth’s and lunar crust discovered after flights to the moon put an end to the “capture” version. Another popular hypothesis was the assumption of the joint formation of the Earth and the Moon (this hypothesis was put forward by the great Immanuel Kant). In accordance with it, the Moon and the Earth were formed simultaneously - from one gas and dust cloud. The nascent proto-Earth gained such mass that particles of the cloud began to rotate in their orbits around it, gradually forming the proto-Moon.
This hypothesis is partly confirmed by the similarity of the isotopes of the Earth and the Moon, but this model does not explain the features of the lunar orbit at all.
To explain these contradictions, American astronomers Bill Hartmann and Donald Davis in 1975 put forward the impact hypothesis, which is currently considered the main one. According to it, when the Solar system was just in its infancy, two protoplanets were formed from a gas and dust cloud revolving around the Sun in the orbit of the future Earth - one of them was the young Earth, and the other (it was smaller, about the size of Mars) was named Theia. Under the influence of gravity, the planets began to move closer together, and 4.4 billion years ago, a grandiose catastrophe finally occurred - a collision of planets. The blow, fortunately, was tangential. Theia was destroyed, and the molten bowels of the earth splashed out into near-Earth orbit from the impact. The Moon was formed from this substance in about a hundred years. The impact spun the Earth - this is where the rapid (in comparison, for example, with Venus) change of days and nights comes from. This hypothesis well explains the inclination of the lunar orbit, the similarity of oxygen isotopes on Earth and the Moon, and the strange internal structure Moons. However, new research published in the journal Nature suggests death blow according to these views.
After conducting a detailed study of samples of lunar rocks obtained by expeditions of the Apollo series of ships in the 70s of the 20th century, experts from the University of Washington issued a negative verdict on the impact hypothesis: “If the old theory were correct, then more than half of the lunar rocks would consist of material from the impact Planetoid Earth. But instead we see that the isotopic composition of the fragments of the Moon is very specific. The heavy isotopes of potassium found in the samples could only have formed under the influence of incredible high temperatures. Only a very powerful collision, in which the planetoid and most of the Earth would evaporate on contact, could cause such an effect."
As a result, scientists have proposed new theory: Instead of a colossal planetary collision, there were multiple collisions with smaller asteroids. The asteroid bombardment threw enough debris into Earth's orbit to form several small satellites, which eventually merged into one large one. This “Protoluna” continued to absorb objects in orbit until it was left in splendid isolation.
The study authors claim that their hypothesis best fits the data. However, skeptics immediately appeared who pointed out that the new hypothesis of the origin of the Moon does not explain all the oddities of the night star. So it’s too early to put an end to the debate about the Moon - the Earth’s satellite still retains its secret...
For most people, the moon is hardly something surprising, because we have the opportunity to observe it in the sky almost every day, and have long ago become accustomed to this phenomenon. Many people do not even know whether it is a planet, a satellite or a star, and why the moon is called the moon. But today we will bring these questions out of the shadows by giving them the correct answers.
Why is the moon called the moon?
As you know, the natural satellite of the earth is not called the moon in all languages and peoples; this is not an international name. And the name with which we are accustomed to call the luminous cosmic body above our heads comes from the Proto-Slavic word “luna”. As for the origin of this Old Church Slavonic word, it is the root of the word “louksna”, which translated into Russian means “bright”. Perhaps this answer is quite rational and explains why the moon is called the moon.
Why is the moon called the Earth's satellite?
As you know, the moon is a satellite of the Earth, and not artificial, but natural. But why was she called that? Answer to this question We will also look at this below.
The Moon is called a satellite of the Earth for the reason that, in comparison with other planets in our solar system, it primarily revolves around the Earth, using its orbit for rotation, and not around the Sun. Of course, the Moon also rotates around our natural star, but it does so along the same trajectory as the Earth, revolving around the Sun along with it.
This is what prompted scientists to call the Moon a natural satellite of the Earth. The characteristic “natural” is present here for the reason that since the beginning of space exploration, people have launched many artificial devices into orbit, which are also satellites.
Why is the moon called a month?
We all know what a month is. This is what they call a partial moon. However, the history of the origin of this name is not known to everyone.
The thing is that previously time was calculated according to lunar calendar, because in the absence of watches and various technologies available to us today, it was quite simple to calculate time using data about the position of the moon. In this calendar there was such a thing as a month, which meant 1/12 of the moon. Over time people transformed this concept, and began to use it to name the partial moon.
Now you know why people call the moon and month that way.
In astronomy, a satellite is a body that revolves around a larger body and is held by the force of its gravity. The Moon is the Earth's satellite. The Earth is a satellite of the Sun. All planets of the solar system, with the exception of Mercury and Venus, have satellites.
Artificial satellites are man-made spacecraft orbiting the Earth or another planet. They are launched for various purposes: for scientific research, for studying weather, for communication.
The Earth-Moon system is unique in the solar system, since no planet has such a large satellite. Moon - the only satellite Earth, but so big and close!
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