"Solar and Lunar Eclipses" Universe PPT download

Description

"Solar and Lunar Eclipses" Universe PPT download

Part 1: Importing new lessons

More than 2,500 years ago, a fierce war broke out between two small countries. There was no victory or defeat for five consecutive years. The corpses of soldiers were strewn in the fields and the common people cried out. The ancient Greek astronomer Thales knew in advance that an astronomical phenomenon was about to occur, and threatened that God would oppose the war and one day make the sun disappear. On that day, the two armies were fighting fiercely. Suddenly, the radiant sun was covered by a black shadow. The black shadow gradually approached from the west edge of the sun to the center. The black shadow became bigger and bigger. After a while, the sun disappeared. Now, the sky is dark, with only a pale yellow mist covering the distant horizon. The soldiers and generals on both sides were so frightened that they stopped fighting and made peace. Later, the two countries even exchanged marriages. According to research, this was an astronomical phenomenon that occurred on May 28, 585 BC.

Do you know what kind of astronomical phenomenon this is?

This astronomical phenomenon is a solar eclipse. Do you know what causes this phenomenon?

Solar and lunar eclipse PPT, part 2: exploring new knowledge

1. Solar eclipse

Certain areas of the Earth sometimes see all or part of the sun's surface obscured, a phenomenon called a solar eclipse.

What are the characteristics of a solar eclipse?

1. The sun is blocked by an object

2. The light-blocking object is round or spherical

3. The object blocking the light is moving

4. The earth, the light-blocking object, and the sun are almost in a straight line

Based on the characteristics of a solar eclipse, imagine the causes of the solar eclipse?

Simulation experiment on the causes of solar eclipse.

One student uses a flashlight to represent the sun, and one student holds a ping pong ball to represent the earth.

A student holds a glass ball. When the moon moves from west to east, he uses the glass ball to rotate once around the ping pong ball to represent the moon's orbit around the earth, and see under what circumstances the sun cannot be seen.

Only when the glass ball turns between the flashlight light and the table tennis ball, and the three are in a straight line, and the distance between the three is appropriate, ensuring that the shadow of the glass ball falls on the table tennis ball, will the "solar eclipse" occur. .

Types of solar eclipse: total solar eclipse, partial solar eclipse, annular solar eclipse.

1. A total solar eclipse occurs when the moon blocks all sunlight.

2. A partial solar eclipse occurs when the moon blocks part of the sun's light.

3. An annular solar eclipse occurs when the moon blocks the central sun's light.

Solar and lunar eclipse PPT, part three: expansion and extension

The radius of the moon is much smaller than that of the sun, so why can it block the sun?

The average distance between the moon and the earth is about 380,000 kilometers. The average distance between the sun and the earth is about 150 million kilometers. Dividing two by two, we get that the distance from the sun to the earth is about 395 times farther than the moon to the earth.

The diameter of the sun is about 1.38 million kilometers, and the diameter of the moon is about more than 3,400 kilometers. Dividing the two, the diameter of the sun is about 395 times that of the moon. Since distance cancels out size, the two celestial bodies appear to be the same size when viewed from above the Earth!

Why there is no annular lunar eclipse

Lunar eclipses are divided into umbral eclipses and penumbral eclipses, and umbral eclipses are further divided into total and partial eclipses. The difference between a total lunar eclipse and a partial lunar eclipse does not depend on the observation location, but on whether the moon completely enters the earth's umbra. During a total lunar eclipse, the entire moon is within the Earth's umbral shadow, thus directly losing the sun's brilliance.

The moon will not experience an annular eclipse because the earth is much larger than the moon, and the distance between the sun and the earth is much greater than the distance between the earth and the moon. Therefore, the length of the earth's umbra is much longer than the length of the moon's umbra, and it also greatly exceeds the distance between the earth and the moon. Even when the Moon is at apogee, the distance between the Moon and the Earth is less than 1/3 of the shortest duration of the Earth's umbra.

In this way, it is impossible for the moon to pass through the earth's false umbral shadow while orbiting the earth, so it is impossible to see an annular lunar eclipse from the earth.

Solar and lunar eclipse PPT, Part 4: Summary of this lesson

1. There are three types of solar eclipses, namely total solar eclipse, partial solar eclipse and annular solar eclipse. There are only total and partial lunar eclipses, but no annular eclipses.

2. Solar and lunar eclipses are astronomical phenomena caused by the movement of the sun, earth and moon.

3. When the moon moves between the sun and the earth, and the earth is in the moon's shadow, a solar eclipse occurs because the moon blocks the sun's light from reaching the earth. A lunar eclipse is when the moon moves into the Earth's shadow, and the Earth blocks the sun's light from reaching the moon.

4. The solar eclipse falls on the first day of the lunar calendar, and the lunar eclipse can only occur on the 15th and 16th day of the lunar calendar.

Solar and lunar eclipse PPT, Part 5: Exercises for this lesson

True or False

1. "Tengu eats the moon" is not a message of disaster, but an astronomical phenomenon. ( )

2. Solar and lunar eclipses can occur at the same time. ( )

3. Lunar eclipses can be divided into total lunar eclipses, partial lunar eclipses, and annular lunar eclipses. ( )

2. Fill in the blanks

1.Some areas on the earth sometimes see the phenomenon of _________ being completely or partially _________. This phenomenon is called a solar eclipse.

2. When the earth moves between _______ and _______, if the three are exactly in a straight line, the earth will block the light from the sun to the moon, and _______ occurs.

3. Multiple choice questions

1. On the following dates, a lunar eclipse may occur ( )

A. Dragon Boat Festival B. Double Ninth Festival C. Mid-Autumn Festival

2. In the simulation experiment of lunar eclipse formation, the flashlight represents ( )

A. sun b. Earth C. Moon

3. The reason why a lunar eclipse occurs is ()

A. Earth's shadow cast on the moon

B. Earth's shadow cast on the sun

C. The moon's shadow casts on the earth

D. The moon's shadow casts on the sun

Solar and lunar eclipse PPT, Part 6: Homework

What did you gain from studying this class?

Keywords: Free download of science PPT courseware for the second volume of sixth grade in the textbook edition, download of solar and lunar eclipse PPT, download of universe PPT, .PPT format;

For more information about the "Cosmic Solar and Lunar Eclipses" PPT courseware, please click on the Cosmic ppt solar and lunar eclipse ppt tab.

"Solar and Lunar Eclipses" universe PPT teaching courseware:

"Solar and Lunar Eclipses" Universe PPT teaching courseware Part One: Review of the previous section 1. What are the main characteristics of craters? 2. What methods can we use to model the formation of craters? 3. Regarding the formation of lunar craters, what are the two main theories, among which...

"Solar and Lunar Eclipses" Universe PPT:

"Solar and Lunar Eclipses" Universe PPT Part One: Solar Eclipse Have you heard of a solar eclipse? Have you ever observed a solar eclipse? If you carefully observe the process diagram of the solar eclipse, what do you find? Based on several characteristics of a solar eclipse, what inferences can we make? The light-blocking object is the moon...

File Info

Update Time: 2024-09-09

This template belongs to science courseware Science Edition for Sixth Grade Science Volume 2 industry PPT template

Preview