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Earth

The Earth

The Earth is the third planet from the Sun. It revolves around the Sun and it also rotates about its axis. It is surrounded by a layer called atmosphere which is mainly composed by oxygen and nitrogen. The Earth has a satellite around: the Moon.

axial tilt obliquity
Axial tilt obliquity. Dennis Nilson. Wikipedia. (CC BY)
Solstice: It is the time of the year when the Earth's Poles are most extremely inclined towards or away from the Sun. Equinox: It's the time of the year when the Sun is exactly over the Equator. Consequently, the hours of daylight and darkness are almost the same everywhere in the Earth.
Axis of rotation:It is an imaginary line that passes through the North and South Poles of the Earth. Axial tilt: It is the inclination or obliquity of the Earth's rotational axis. Revolution: It is the movement of the Earth around the Sun. A complete orbit takes 365.2 days.

Rotation: It is the movement of the Earth on its axis. A complete turn takes 23 hours and 56 minutes. Seasons: Periods of the year with different exposure to Sun's rays due to the Earth's 23º tilt in its axis. This obliquity implies that the Southern Hemisphere is more exposed to the Sun's rays while the Northern Hemisphere is less exposed and vice versa. Leap year: It is a year that contains an extra day in February because the Earth completes one revolution around the Sun in about 365 days and 6 hours. Over a period of 4 years, the extra 6 hours become a day.

Equinox

Orbital relations of the Solstice, Equinox & Intervening Seasons. Colivine. Pixabay. (CCO)

I'm ready to look at the sky

Star trails

Star trails. PTNorbert. Pixabay. (Licencia Pixabay)

 

Activity 1

1. Complete the words with the missing letters.
I'm learning about the Earth 1- TI 2- SOL 3- HEMI
4- SE 5- ROT 6- REVO
7- OR 8- EQU 7- OBLI

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Activity 2

2. Listen and write the word you hear.
1. 1. 2. 2.
3. 3. 4. 4.
5. 5. 6. 6.
7. 7. 8. 8.

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Activity 3

3a. Listen and write the word that corresponds to each definition.
A- A- B-  B-
C- C- D-  D-
E- D- F- F-
3b. Listen to the definitions and complete with the right words.
         
It is a year that contains an day in because the Earth completes one around the Sun in about 365 days and 6 hours. Over a period of 4 , the extra 6 hours become a day. It's the time of the year when the Sun is exactly over the . Consequently, the hours of and are almost the same everywhere in the Earth.

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Activity 4

4. Choose the right word for each sentence.
a. The day and the night last almost the same time when there is an .

The Earth from the ISS

View of planet Earth from the International Space Station. Jean Beaufort.  Public Domain Pictures. (Public Domain).

.

b. The Earth around the Sun.
c. 365.2 days refer to a .
d. 6 hours over a period of 4 years make a .
e. When there is an extra day in February, we call it a year.
f. 23º refers to the in the Earth's axis.
g. 23 hours and 56 minutes refer to a .
h. The axis of rotation is an imaginary line that goes through the .

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Extra activity

Watch this video about the seasons and say if the sentences are TRUE (T) or FALSE (F). You can also have a look at the script here.

Seasons. Earth rocks. YouTube. (CC0)

1. It takes the Earth 24 hours approximately to make a full rotation around the Sun.
2.The Earth's orbit around the Sun describes a perfect circle.
3.The Earth is warmer when it is nearer the Sun.
4.The tilt on the Earth axis has a great effect on seasons.
5.The Tropic of Capricorn is in the Northern Hemisphere.
6. At the solstice on June 22nd, it is summer in the Northern Hemisphere.
Teamwork  In pairs prepare to give the rest of students a clear explanation about the reasons why you consider the previous sentences are true or false.


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Astronomical Models

Geocentric Theory

Line art drawing of Ptolemaic system. Pearson Scott Foresman. Wikimedia Commons. (Public Domain).

ASTRONOMICAL MODELS

Ancient Greeks, such as the astronomer Ptolemy, and Roman and medieval philosophers, thought that the Earth was the centre of the Universe and the Sun, the Moon, the stars and the planets revolved around it. This was called the Geocentric Theory.

From the 15th century onwards, astronomers such as Copernicus (1473-1543), Galileo (1564-1642) and Kepler (1571-1630) realised that the Sun was in the centre of our Solar System and the planets, including the Earth, moved around it. This is called the Heliocentric Theory.

Read the text. Are the statements true (T) or false (F)?

Heliocentrism

Sistema heliocéntrico de Copérnico   simplificado. Unknown. Wikipedia. (Public Domain).

- Ptolemy was Roman.
- Ptolemy thought the Sun was the centre of the Universe.
- Copernicus was born in the 15th century.
- Galileo was in favour of the Heliocentric Theory.
- The Moon is in the centre of the solar system according to the Heliocentric Theory.

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Projects

PROJECT 1 PROJECT 2 PROJECT 3
Make a model of the Earth and explain facts about it to the rest of students. Quantity of water, oceans, continents, capes, the coldest/hottest place, the biggest island, the poles, hemispheres, tropics, etc.

Search the Internet to find answers for these questions:

- When do equinoxes occur?

- When do solstices occur?

- What is the elliptic plane of the Earth?

- Why seasons are different in the Northern and Southern hemispheres?

When you have all the information, make a poster and present the information to the rest of students.
The Earth and Maths. Compare the radius and diameter of the Earth to distances around you. Create a slideshow and present the facts to the rest of students.