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Welcome to Class !!
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In today’s Basic Science class, We will be discussing Earth in Space. We hope you enjoy the class!
EARTH IN SPACE
The planet on which we live is called the Earth and it is currently the only planet that is said to support life conveniently.
Our solar system consists of the Sun and nine natural heavenly bodies which move around it. These bodies are called the planets.
They are in order, beginning from the nearest to the Sun and moving outwards; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. All the planets revolve around the Sun with each in its own orbit.
MOVEMENTS OF THE EARTH
The Earth carries out two types of movements in space and these movements are what results in day and night, and also the different seasons we have in a year. The movements are:
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ROTATION OF THE EARTH:
This is the movement of the Earth on its own axis. The Earth completes one rotation in 24 hours (a day). The rotation of the Earth brings about night and day. The Sun sheds light on the Earth and the part of the Earth which faces the Sun, at a particular time, has its day. The Sun is static and does not move, the planets all revolve around the Sun. As the Earth rotates from west to east, the areas which have day move from daylight into their night, while those having their night in turn, move into their day.
This is how day and night follow each other regularly. The Earth completes one rotation in 24 hours and so, one day and one night add up to 24 hours. You can try out a simple experiment to better understand the rotation of the Earth with an Earth globe and a torch/flashlight. The torch should be switched on and shone directly on the Earth globe while someone gently rotates the Earth globe on its axis. You will notice that only a part of the Earth globe receives light while the other part is darkness, and as the Earth globe keeps rotating, those parts that had light gradually become dark. This simple experiment explains the rotation of the Earth.
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REVOLUTION OF THE EARTH:
This is the movement of the Earth along a circular path around the Sun. This movement explains why a year is 365 days long because it takes the Earth 365.24 days to revolve around the Sun.
During this period, the Earth is angled differently towards the Sun. The different angles of the Earth result in different Sun intensities and so, we get four different seasons which are summer, winter, autumn and spring.
As mentioned earlier, it takes the earth approximately 365.24 days to revolve around the Sun. The .24 is converted to 6 hours but is usually ignored for the sake of convenience. These six hours is not totally thrown away because 6 hours saved every year will make one day (24 hours) over a span of four years. This extra day is usually added to the month of February, therefore, every fourth year, February is 29 days instead of 28 days. Any year this happens, the year has 366 days and it is called a leap year.
ECLIPSE
There are certain times when one heavenly body such as a moon or planet moves into the shadow of another heavenly body; this occurrence is referred to as an eclipse.
There are two types of eclipses on Earth: an eclipse of the moon also known as lunar eclipse and an eclipse of the Sun also known as solar eclipse.
The moon is the only satellite of the Earth and it moves in an orbit around Earth, and at the same time, Earth orbits the sun. Sometimes, the Earth moves between the sun and the moon in the course of its movement and when this happens, Earth blocks the sunlight that is normally reflected by the moon. (This sunlight is what causes the moon to shine; the moon does not have a light of its own.) Instead of light hitting the moon’s surface, Earth’s shadow falls on it because of the Earth’s obstruction and this results in an eclipse of the moon also known as the lunar eclipse.
A lunar eclipse can occur only when the moon is full and can either be full or partial.
Sometimes when the moon orbits Earth, it moves between the sun and Earth. When this happens, the moon blocks the light of the Sun from reaching Earth. This causes an eclipse of the sun or solar eclipse. During a solar eclipse, the moon casts a shadow onto Earth.
The movements of Earth with respect to its orbit, the Sun and the Moon results in so many occurrences as we have explained above.
We have come to the end of this class. We do hope you enjoyed the class?
Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.
In our next class, we will be talking about Human Development II. We are very much eager to meet you there.
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