Our Universe
The universe is vast. The solar system forms a very small part of the universe. Our earth is one of the eight planets of the solar system. Yuri Gagarin was the first man to go into space. Valentina Tereshkova was the first woman to go into space. Rakesh Sharma was the first Indian man and later Kalpana Chawla became the first Indian woman to go into space.
Solar System
Moon
As the earth moves around the sun, it is accompanied by the moon. Even though the moon is earth's nearest neighbour in space, it is 3,84,400 km away from the earth’s The moon is 4500 million years old, the same age as the earth. The moon is called the earth's natural satellite because it revolves around the earth.
Why does the moon shine at night? The moon shines because it reflects the sun's light falling on it.
The surface of the moon is made up of plains, valleys and mountains. There are big holes called craters all over the moon. These craters are round and deep. A dark grey dust covers the surface of the moon.
Americans Neil Armstrong, Edwin Aldrin and Michael Collins were the first people to visit the moon. They landed on the moon on 21 July 1969 in their spacecraft Apollo 11. Neil Armstrong was the first person to step on the moon.
Moon
The Moon and Tides
The rising and falling of the level of water in the sea are called tides. Tides are caused by the gravitational pulls of the moon and the sun. The moon attracts the ocean water with stronger force of attraction than that of the sun, because the moon is much closer to the earth than the sun.
Eclipse
An eclipse is a shadow that makes the sun or the moon totally or partially invisible for some time. The sun is the source of light and the earth and the moon are the objects that come in the path of this light and cast their own shadows. As the earth and the moon keep moving, their positions keep changing. Thus, their shadows also keep changing.
Solar Eclipse
Sometimes the moon comes between the sun and the earth. When this happens, the moon. obstructs the light of the sun and casts its shadow on the earth. The people living in this part of the earth can see only a part of the sun or not see it at all. This is a solar eclipse. Once the moon moves out of this position, the sun can be seen again.
If the complete disc of the sun is covered by the shadow of the moon, it is called a total solar eclipse. If
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