Astronomy lesson on the topic “Terrestrial Planets” lesson plan on the topic


Summary of the open lesson “Terrestrial Planets”

The electric field above the Earth's surface has an average strength of about 100 V/m and is directed vertically downwards - this is the so-called clear weather field, but this field experiences significant (both periodic and irregular) variations.

Moon.

The Moon is the natural satellite of the Earth and the closest celestial body to us. The average distance to the Moon is 384,000 kilometers, the diameter of the Moon is about 3,476 km. The average density of the Moon is 3.347 g/cm³, or about 0.607 the average density of the Earth. The mass of the satellite is 73 trillion tons. The acceleration of gravity on the surface of the Moon is 1.623 m/s².

The Moon moves around the Earth at an average speed of 1.02 km/sec in a roughly elliptical orbit in the same direction in which the vast majority of other bodies in the Solar System move, that is, counterclockwise when looking at the Moon's orbit from the North Pole. The period of revolution of the Moon around the Earth, the so-called sidereal month, is equal to 27.321661 average days, but is subject to slight fluctuations and a very small secular reduction.

Not being protected by the atmosphere, the surface of the Moon heats up to +110°C during the day and cools down to -120°C at night, however, as radio observations have shown, these huge temperature fluctuations penetrate only a few decimeters deep due to the extremely weak thermal conductivity of the surface layers.

The relief of the lunar surface was mainly clarified as a result of many years of telescopic observations. The “lunar seas,” occupying about 40% of the visible surface of the Moon, are flat lowlands intersected by cracks and low winding ridges; There are relatively few large craters in the seas. Many seas are surrounded by concentric ring ridges. The remaining, lighter surface is covered with numerous craters, ring-shaped ridges, grooves, and so on.

— Analysis of the speech by experts (Completeness of the message, explanation of the cause of the phenomena, etc.)

Mars.

General information.

Mars is the fourth planet of the solar system. Mars - from the Greek "Mas" - male power - the god of war. According to its basic physical characteristics, Mars belongs to the terrestrial planets. In diameter it is almost half the size of Earth and Venus. The average distance from the Sun is 1.52 AU. The equatorial radius is 3380 km. The average density of the planet is 3950 kg/m³. Mars has two satellites - Phobos and Deimos.

Atmosphere.

The planet is shrouded in a gaseous shell - an atmosphere that has a lower density than the earth's. Even in the deep depressions of Mars, where the atmospheric pressure is greatest, it is approximately 100 times less than at the surface of the Earth, and at the level of Martian mountain peaks it is 500-1000 times less. Its composition resembles the atmosphere of Venus and contains 95.3% carbon dioxide with an admixture of 2.7% nitrogen, 1.6% argon, 0.07% carbon monoxide, 0.13% oxygen and approximately 0.03% water vapor, the content which varies, as well as admixtures of neon, krypton, and xenon. The average temperature on Mars is significantly lower than on Earth, about -40 ° C. Under the most favorable conditions in the summer on the daytime half of the planet, the air warms up to 20 ° C - a completely acceptable temperature for the inhabitants of the Earth . But on a winter night, frost can reach -125° C. Such sudden temperature changes are caused by the fact that the thin atmosphere of Mars is not able to retain heat for a long time.

Characteristics of planetary satellites

Terrestrial planets are too small, they have practically no satellites, unlike giant planets. It is currently known that the Earth (Moon) and Mars (Phobos, Deimos) have satellites. The most famous satellite for the inhabitants of our planet is the Moon. We can see this celestial body from the window, we feel its influence on the World Ocean, and it is this object that has been studied best in space.

Moon

The Earth has been under the observation of astronomers for many centuries. Since ancient times, scientists have expressed the view that the Earth is influenced by a certain celestial body that controls the ebb and flow of tides and participates in eclipses. Theoretically, all these assumptions turned out to be correct. This same controller turned out to be the Earth's natural satellite - the Moon. So far this is one officially confirmed satellite.

Sometimes astronomers are divided in opinion, expressing points of view about the presence of other satellites, confusing them with quasi-satellites, asteroids and other near-Earth objects that can converge in orbital space. At the same time, all these bodies revolve around the Sun, and the Moon still revolves around the Earth.

Like the Earth, the Moon has a core in its structure; the satellite is covered on top by three layers of mantle and the lunar crust. The surface of the Moon is heterogeneous, and this can be seen even from Earth using the most ordinary telescope. Due to the absence of an atmospheric layer on the earth's satellite, its surface is susceptible to meteorite attacks. If a dense air shell covered the Moon, then the meteorites would simply burn up in the atmosphere.

In July 1969, American astronauts landed on the Moon and discovered that its surface was covered with dust, iron, basalt, silicon, and other elements in the minority. The visible dark inclusions on the Earth's side were called seas; these are large craters and faults after a meteorite invasion. The light parts were designated as mountains, because... they rise above the meteorite pits. In 1651, Giovanni Raccioli compiled a map of the Moon, where he outlined the lunar seas.

The Moon is several times smaller than the Earth. We can observe these facts in the table below. Despite the difference in mass, it can be noted that the Moon also exhibits surface movement. Due to the moonquake, new seams are formed, which can be seen in photographs of lunar research rovers. The maximum scale of a moonquake is 5.5 points, the average duration is 10 minutes. While an earthquake with such a magnitude lasts a maximum of 2-3 minutes.

Phobos and Deimos

Deimos was discovered first. According to one theory, Phobos and Deimos are previously captured asteroids that ended up in the same orbit with Mars. Scientists also suggest that dust and small asteroids with a radius of 50-100 meters located between the satellites may also be directly related to the Red Planet, but direct evidence does not yet exist.

The surface of the satellites is monoliths. Moreover, Phobos has weaker gravity, which is confirmed by its low density. In the course of research, scientists have discovered that the first 100 m of the satellite surface is covered by regolith. In composition, both cosmic bodies are 95% similar to asteroids. What is noteworthy is that Phobos and Deimos have a completely irregular shape, unlike the usual round Moon, these two bodies are similar to sea pebbles, dotted with craters.

Due to such a rapid rotation, Phobos is slowly but surely approaching Mars. Presumably, subsequently, the tidal forces of the planet will tear apart the satellite and leave another crater on the red surface.

Open lesson on astronomy in grade 10 on the topic: “Terrestrial planets”

Lesson plan on the topic:

Terrestrial planets.

Goal: To form general ideas about the features of the nature of the terrestrial planets.

Develop cognitive activity in students.

To foster a sense of responsibility for our planet, the Universe as a whole.

1. Organizational moment.

2. Motivation

The Solar System contains planets with their moons, dwarf planets, comets, asteroids, meteors and meteorites held by the gravity of the Sun. If we don’t talk about the Sun, then the main inhabitants of the Solar system are the planets wandering in the Universe. Planets are the most massive bodies moving around the Sun in orbits. If the distance from the Sun to the Earth is 150 million km as a conventional unit, then the distance to the most distant planet will be a conventional 40 units - 6 billion km! The planets in the solar system are divided into two groups: the terrestrial planets (they got their name for their resemblance to our planet Earth) Mercury, Venus, Mars and the giant planets Jupiter, Saturn, Uranus and Neptune. Let's see what the terrestrial planets have in common and how they differ from each other. (Slides 2,3)

3. Studying a new topic.

Plan Characteristics of the planets:

- the distance from the Sun to the planet, - the diameter of the planet, - the relief and color of the planet, - the appearance in the starry sky, - the composition of the atmosphere, - the temperature on the surface of the planet, - revolution around its axis, - revolution around the Sun; — presence and characteristics of large satellites.

1) Mercury. (Slides 4,5)

Mercury is the first planet of the solar system. The average distance from the Sun is 0.387 astronomical units (58 million km). The planet moves along a highly elongated elliptical orbit with perihelion (the shortest distance from the planet to the Sun) of 45.9 million km and aphelion (the maximum distance from the planet to the Sun) of 69.7 million km. The distance of the planet to the Earth varies from

82 to 217 million km. Mercury is the smallest terrestrial planet, 2 times smaller than Earth. Its radius is only 2439 km.

The surface of Mercury is covered with thousands of craters caused by collisions with meteors. In conditions of almost no atmosphere, falling meteors do not burn up due to friction and safely reach the surface of the planet. Along with this, Mercury contains hills and plains. One of the most prominent plains of Mercury is the Plain of Heat. Its size is 1300 km. in diameter. The appearance of the plain is prescribed

collision of a planet with a massive asteroid. Under the most favorable conditions, the planet can be seen early in the morning in the east before sunrise or in the west after sunset. Therefore, in ancient times, Mercury was often mistaken for two different luminaries (morning and evening). In its appearance, Mercury is very similar to the Moon; it also changes phases: from a narrow crescent to a light circle.

The atmosphere of Mercury is unique and consists mainly of oxygen, sodium and helium. Due to the high temperature of the planet, atoms of the atmosphere are constantly escaping into space, but are also constantly replenished by atoms brought by the solar wind. Due to the very strong rarefaction, the concept of the atmosphere of Mercury is rather conditional; the atmospheric pressure of Mercury is 500,000,000,000 times less than that of Earth, and this is comparable to

ordinary vacuum. Since Mercury is the closest planet to the Sun, its surface receives a large share of solar radiation, about 10 times more than the Earth, so the temperature on its surface is quite high and reaches 467°C. Night temperatures are much lower and drop to minus 183°C. Mercury moves in orbit at an average speed of 47.9 km/sec and makes a full revolution around the Sun in 87.97 Earth days; the planet rotates quite slowly around its own axis; in two revolutions around the Sun, the planet makes approximately three revolutions, which is 58.65 earthly days.

2) Venus. (Slides 6-9)

Venus is the second most distant planet from the Sun in the solar system and the third brightest object in the sky; its brilliance is second only to that of the Sun and Moon. Venus is one of the most beautiful luminaries in the sky, so the ancient Romans gave her the name of the goddess of love and beauty. Venus is an inner planet. It is one of the planets known to mankind since ancient times. The average distance of Venus from the Sun is 108 million km.

Venus is quite close in size to Earth. The radius of the planet is 6051.8 km.

The relief of Venus consists of vast plains and mountain ranges. Volcanic eruptions occur on the planet, and numerous craters have been identified.

Finding Venus in the sky is easier than any other planet. Its dense clouds perfectly reflect sunlight, making the planet bright. Since Venus's orbit is closer to the Sun than the Earth's, Venus in our sky never moves very far from the Sun. For a few weeks every seven months, Venus is the brightest object in the western sky in the evenings. It is called the "evening star".

The atmosphere on Venus was discovered by M.V. Lomonosov June 6, 1761, it consists mainly of carbon dioxide (96%) and nitrogen (almost 4%). Water vapor and oxygen are contained in it in small quantities (0.02% and 0.1%). The temperature on the surface of Venus is about 475 °C, which is higher than the surface temperature of Mercury, which is twice closer to the Sun. The reason for the high temperature on Venus is the greenhouse effect created by the dense carbon dioxide atmosphere, so any existence of liquid water on the surface of Venus is excluded.

Venus rotates on its axis, in the opposite direction to the direction of rotation of most planets. Almost every planet in the solar system can boast of some kind of space record. Venus “boasts” of its densest atmosphere among the terrestrial planets and the slowest rotation around its axis. It makes one revolution every 243 days. The length of a solar day on the planet is 116.8 Earth days.

3) Earth.
(Slides 10-17)
Earth is the third planet from the Sun in the solar system. The shape of the Earth is close to an ellipsoid, flattened at the poles and stretched in the equatorial zone. The average radius of the Earth is 6371.032 km, polar - 6356.777 km, equatorial - 6378.160 km. Weight - 5.976*1024 kg. The average density of the Earth is 5518 kg/m³. The Earth's surface area is 510.2 million km², of which approximately 70.8% is in the World Ocean. Its average depth is about 3.8 km, the maximum (Mariana Trench in the Pacific Ocean) is 11.022 km; water volume is 1370 million km³, average salinity is 35 g/l. Land makes up 29.2% respectively and forms six continents and islands. It rises above sea level by an average of 875 m; highest height (peak of Chomolungma in the Himalayas) 8848 m. Mountains occupy over 1/3 of the land surface. Deserts cover about 20% of the land surface, savannas and woodlands - about 20%, forests - about 30%, glaciers - over 10%. Over 10% of the land is occupied by agricultural land. The Earth has only one satellite - the Moon. Thanks to its unique, perhaps unique, natural conditions in the Universe, the Earth became the place where organic life arose and developed. According to modern cosmogonic concepts, the planet formed approximately 4.6 - 4.7 billion years ago from a protoplanetary cloud captured by the gravity of the Sun. The formation of the first, most ancient of the studied rocks took 100-200 million years. About 3.5 billion years ago, conditions favorable for the emergence of life arose. Homo sapiens (Homo sapiens) as a species appeared about half a million years ago, and the formation of the modern type of man dates back to the time of the retreat of the first glacier, that is, about 40 thousand years ago.

Movement. Like other planets, it moves around the Sun in an elliptical orbit with an eccentricity of 0.017. The distance from the Earth to the Sun at different points in the orbit is not the same. The average distance is about 149.6 million km. As our planet moves around the Sun, the plane of the Earth's equator moves parallel to itself in such a way that in some parts of the orbit the Earth is inclined towards the Sun with its northern hemisphere, and in others - with its southern hemisphere. The period of revolution around the Sun is 365.256 days, with a daily rotation of 23 hours 56 minutes. The Earth's rotation axis is located at an angle of 66.5º to the plane of its movement around the Sun.

Atmosphere.

The Earth's atmosphere consists of 78% nitrogen and 21% oxygen (there are very few other gases in the atmosphere); it is the result of long evolution under the influence of geological, chemical and biological processes. It is possible that the Earth's primordial atmosphere was rich in hydrogen, which then escaped. Degassing of the subsoil filled the atmosphere with carbon dioxide and water vapor. But the steam condensed in the oceans, and the carbon dioxide became trapped in carbonate rocks. Thus, nitrogen remained in the atmosphere, and oxygen appeared gradually as a result of the life activity of the biosphere. Even 600 million years ago, the oxygen content in the air was 100 times lower than it is today.

4) Mars. (Slides 18-27)

Mars is the first planet in the solar system after Earth, to which for some time people began to show special interest, caused by the hope that developed extraterrestrial life exists there.

The planet is named Mars in honor of the ancient Roman god of war for its blood-red color, due to the presence of iron oxide in the soil of Mars.

Mars is the fourth most distant planet from the Sun and the seventh largest planet in the solar system. It can be seen from Earth with the naked eye. It is second in brightness only to Venus, the Moon and the Sun.

Mars is almost half the size of Earth - its equatorial radius is 3,396.9 kilometers (53.2% of Earth's). The surface area of ​​Mars is approximately equal to the land area on Earth.

The average distance from Mars to the Sun is 228 million kilometers, the period of revolution around the Sun is 687 Earth days.

The minimum distance from Mars to Earth is 55.75 million kilometers, the maximum is about 401 million kilometers.

But the gravity on Mars is very small, hence all the “troubles”. It cannot hold the atmosphere, without which there is no life. The atmosphere is very rarefied, that is, not dense, its composition resembles that of Venus. The temperature in summer during the day is +20°C, quite acceptable for life, but at night in winter -125°C. A thin atmosphere does not retain heat. Mars turned out to be a waterless, cold desert, more similar to the Moon than to our Earth, almost half the size of the Earth and nine times the size of the Earth.

The planet is red because there is a lot of iron oxide in the surface rocks. Mars can boast of its high mountains and volcanoes. The highest is Olympus volcano. Its height is 27 km, which is 3 times higher than the highest peak on Earth - Mount Everest.

Mars has two natural satellites - Phobos and Deimos, and three artificial satellites.

4. Generalization and consolidation of the material.

Knowledge control.

There are ten questions in total, each of which has answer options.

Questions:

1. Select terrestrial planets:

A) Mercury, Venus, Mars, Earth

B) Earth, Jupiter Saturn, Mars

B) Mars, Earth, Uranus, Jupiter

2. Which planet in the solar system has the shortest year?

a) Earth; b) Mercury; c) Venus.

3. Which planet has the longest day compared to its year?

a) Pluto; b) Mercury; c) Jupiter.

4. Which of the terrestrial planets is closest to Earth?

a) Mars; b) Venus; c) Mercury.

5. Which planet is the brightest in the night sky?

a) Mercury; b) Venus; c) Jupiter.

6.The names of the satellites of this planet are translated as “fear” and “horror”. What planet are we talking about?

a) Jupiter; b) Pluto; c) Mars.

7. Which planet is called red?

a) Jupiter; b) Mars; c) Mercury.

(Answers: 1-b, 2-b, 3-b, 4-b, 5-b, 6-c, 7-b). Students must answer these questions
within three minutes.
5. Physical training

6. Play OK to lesson No. 19

7. Computer testing

8. D/z

§15, fill out the table

9.
Reflection.
Analysis of your emotional state: write answers to the questions:

  1. did you like the lesson?
  2. How did you work in the lesson?
  3. what did you miss?
relief and color of the planet Mass, radius Planet density Presence and composition of the atmosphere Temperature range on the planet's surface a magnetic field revolution around the Sun and around its axis satellites
Earth
Mercury
Venus
Mars

Terrestrial planets (Mercury, Venus, Earth, Mars)

Rice. 56. Mercury

Planet Mercury. This is the planet closest to the Sun (Fig. 56). Named after the ancient Roman god of trade. Mercury is similar in size and mass to the Moon. He also resembles her in appearance. On the surface of this planet there are mountains and craters, like on the Moon.

Craters are rounded depressions 100-200 km wide and several kilometers deep. Since Mercury is close to the Sun (58 million km), its surface heats up to 400 °C. Mercury rotates very slowly around its axis - a day on it is about 176 Earth days, and a year lasts only 88 days.

Rice. 57. Venus

The planet Venus is named after the ancient Roman goddess of love and beauty (Fig. 57). In the sky it shines brighter than the stars and is clearly visible to the naked eye. Venus is smaller in size than Earth and has a dense cloudy atmosphere consisting mainly of carbon dioxide. This allows heat to be retained, so the temperature on Venus is even higher than on Mercury. The surface of Venus is mostly plains with low hills, but there are mountainous areas and even a huge volcano 12 km high. A year on Venus is 224.7 Earth days, and a day is almost 117 times longer than on Earth.

Rice. 58. Earth

Planet Earth is the largest planet in the terrestrial group and the only one with an air envelope (Fig. 58). The air envelope of the planet is called the atmosphere. It consists primarily of nitrogen, oxygen and carbon dioxide. More than 70% of the Earth's surface is covered with water. The presence of atmosphere, water, and moderate temperature create ideal conditions for the existence of life on planet Earth. Other planets do not have such conditions.

The Earth rotates around the Sun in 365.3 days, and a day is 24 hours long. Material from the site //iEssay.ru

Rice. 59. Mars

Planet Mars is the fourth planet of the solar system (Fig. 59). Named after the ancient Roman god of war. The surface of Mars is rich in iron, which is why the planet has a red color. Mars is half the size of Earth. The atmosphere of Mars consists primarily of carbon dioxide. The average temperature on the surface is -70 °C and only at the equator rises slightly above 0 °C. The surface of the planet is deserts, craters, mountains. Some of them are quite tall. For example, the height of the extinct Olympus volcano is 27 km. A year on Mars is 1.9 Earth years, and the length of a day is 24 hours 39 minutes.

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On this page there is material on the following topics:

  • message on terrestrial planets
  • short message about planet venus

Table “Comparative characteristics of the terrestrial planets”

CharacteristicsMercuryVenusEarthMars
Radius2439.7 km6051.8 km6371.0 km3389.5 km
Weight3.33•1023 kg4.86•1024 kg5.97•1024 kg6.41•1023 kg
Period of rotation around its own axis58,646 days243.023 days23 hours 56 minutes24 hours 37 minutes
Period of revolution around the Sun87,969 days224.7 days365.25 days686.98 days
Minimum distance to the Sun (Perihelion)69 million km108.9 million km147.1 million km206.7 million km
Maximum distance to the Sun (Aphelion)46 million km107.5 million km152.1 million km249.2 million km
Maximum surface temperature427°С476°С56.7°C35°С
Minimum surface temperature–193°С460°C–89.2°С–135°С

List of sources used
• https://planetologia.ru/celestial-bodies/849-general-characteristics-of-the-terrestrial-planets • https://v-kosmose.com/planetyi-zemnoy-gruppyi/ • https:/ /ru.wikipedia.org/wiki/Mercury • https://ru.wikipedia.org/wiki/Venus • https://ru.wikipedia.org/wiki/Earth • https://ru.wikipedia.org/wiki /Mars

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