"Earth's Cosmic Environment" The Earth in the Universe PPT

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"Earth's Cosmic Environment" The Earth in the Universe PPT

Part One Content: Universe: the general name of everything in the world

celestial body

Celestial bodies: the existence forms of matter in the universe; divided into natural celestial bodies and artificial celestial bodies;

Note: The celestial bodies mentioned in this book are generally natural celestial bodies

Celestial system

2. Celestial body system: Universal gravity and the eternal motion of celestial bodies maintain the relationship between celestial bodies and form a multi-level celestial body system.

[Note: Celestial bodies in motion attract and revolve around each other to form a celestial body system; a celestial body system must be composed of two or more celestial bodies. 】

Earth’s cosmic environment PPT, part 2: (1) Earth’s position in the universe

(1) Classification of celestial bodies:

Natural celestial bodies: nebulae, stars, planets, meteoroids, satellites, comets, etc.

Artificial celestial bodies: artificial satellites, space shuttles, spacecraft, etc.

[Knowledge Expansion]——Location conditions of space launch base and return base:

1. Conditions for selecting the location of the space launch base:

(1) Latitude position: The lower the latitude, the greater the linear speed of the earth's rotation and the greater the centrifugal force of inertia, which can increase the speed of the spacecraft during launch and save fuel; conversely, more fuel will be consumed.

(2) Climate and meteorological conditions: dry climate, scarce precipitation; clear weather and high visibility; try to choose areas with more sunny weather, light air pollution, and high transparency.

(3) Terrain conditions: flat and open, with relatively high terrain. Flat and open terrain is conducive to tracking and detection by ground equipment, while high terrain results in a greater linear speed of the earth's rotation.

(4) Geological conditions: The geology is stable.

(5) Traffic location: There must be convenient traffic conditions to facilitate the transportation of large equipment.

(6) Population density conditions: It is best for space bases to be located in areas with low population density to ensure safety.

2. Conditions for choosing a location for space return to base:

(1) Terrain conditions: flat and open.

(2) Population density conditions: sparsely populated.

(3) Hydrological conditions: few large rivers and lakes.

(4) Meteorological conditions: The weather conditions are good and the air visibility is high.

(2) Natural celestial bodies

Star - a celestial body with huge size and mass, capable of emitting heat and light, the typical star "sun"

Nebula - a cloudy appearance of interstellar material composed of gas and dust

Meteoroids - fleeting celestial comets - trailing long tails

Planet - A celestial body that does not emit light or heat. The light and heat come from the surrounding stars. like "earth"

Satellite - does not emit light or heat, orbits the planet

Earth’s cosmic environment PPT, part three: (2) Levels of celestial systems

(1) Milky Way and Milky Way

① Milky Way: The projection of the main body of the Milky Way on the celestial sphere as seen by observers on earth appears as a milky white bright band with irregular boundaries in the clear night sky.

② Milky Way: The galaxy named after the Milky Way is composed of a large number of stars, nebulae and interstellar matter. The main part of the Milky Way is a round and flat disk with a diameter of about 80,000 light-years. It is thick in the middle and thin at the edge, shaped like a discus. The disk is formed during auspicious rotation and forms some spiral arms, with the sun located on one of the spiral arms.

(2) Extragalactic galaxies and observable universe

① Extragalactic galaxies: Extragalactic galaxies are composed of a large number of stars outside the Milky Way, but because of their long distance, they appear as blurry points of light on the outside, so they are also called "extragalactic nebulae".

② Observable universe: The celestial body level higher than the galaxy cluster is the total galaxy. It includes the entire universe that can be covered by existing observation tools and the 1 billion galaxies that have been discovered.

(3) Multi-level celestial body system

①Conditions for the formation of celestial body systems: the eternal motion of celestial bodies and universal gravitation.

②Level of celestial system:

③ Nebula: Cloudy objects composed of electrical dust and gas in the Milky Way.

④Solar system: The central celestial body is the sun, and the planet closest to the sun is Mercury; the distance between the sun and the earth is about 150 million kilometers.

⑤Earth-Moon System: The central celestial body is the Earth, the planet closest to the Earth is Venus, and the one that humans are currently exploring and preparing to immigrate to is Mars. The distance between the moon and the earth is approximately 384,000 kilometers.

Earth’s cosmic environment PPT, part 4 content: (3) Planet Earth

1. Ordinariness: In terms of appearance and location in the solar system, the Earth is an ordinary planet.

(1) Classification

Terrestrial planets: close to the sun, with solid surfaces and small sizes, including A. Mercury, B. Venus, C. Earth, D. Mars

Giant planets: Far away from the sun, mainly composed of gas, huge in size; including E Jupiter, F Saturn

Aphelion planets: far away from the sun, mainly composed of gas, far away from the sun; including G Uranus, H Neptune

(2) Movement characteristics:

The direction of revolution is the same;

The orbits of revolution are coplanar;

The shape of the revolution orbit is nearly circular;

Note: ① There is an asteroid belt between Mars and Jupiter;

② Halley’s Comet: moves clockwise, with a period of 76 years;

③Pluto: The direction of revolution is counterclockwise;

④The rotation direction of Venus is from east to west

[Thinking] Explain that the earth is an ordinary planet in the solar system

Answer ideas: ① The motion characteristics of the Earth are not much different from those of other planets;

②The mass, volume and other structural characteristics of the Earth are not much different from those of terrestrial planets.

2. Speciality - the only planet currently known to have life.

External: The cosmic environment in which the earth is located is very safe

A. The central celestial body of the solar system, the sun, is in its prime, stable, and has stable sunlight.

B. The interstellar space where the earth is located is safe and orderly, and the planets orbit safely;

Internal (self):

A. Suitable sunlight and temperature range. The distance between the earth and the sun is moderate, and the rotation and revolution periods are moderate.

B. Just right atmospheric thickness and atmospheric composition. The Earth's mass and volume are moderate, and its gravity can cause a large amount of gas to gather around the Earth, forming an atmosphere surrounding the Earth.

C. Sufficient water (liquid water) - the shrinkage of the original earth's volume and the decay of internal radioactive elements generated heat. The temperature inside the earth gradually increased and water vapor was continuously produced; the ocean is the cradle of life, and the earliest single-cell organisms on the earth appeared. in the ocean.

Earth’s cosmic environment PPT, part 5: knowledge supplement: the best of the eight planets

(1) The closest to the sun is Mercury, and the farthest is Neptune.

(2) The closest to the earth is Venus, and the farthest is Neptune.

(3) Jupiter has the largest mass and volume, and Mercury has the smallest.

(4) The Earth has the highest average density, and Saturn has the smallest density.

(5) The longest rotation period is Venus, and the shortest is Jupiter.

Keywords: PPT courseware for high school geography required by the People's Education Press is available for free download, Earth's cosmic environment PPT download, Earth in the universe PPT download, .PPT format;

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Update Time: 2024-10-03

This template belongs to Geography courseware People's Education Press High School Geography Compulsory Course 1 industry PPT template

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