In this chapter, we are going to learn about some bodies in the universe and solar system.
Do you wonder why can’t we see the moon and all those bright tiny objects during that time? It is because the very bright light of the sun does not allow us to see all these bright objects in the night sky.
Shining objects in the universe are wholly called CELESTIAL BODIES.
STARS
The bodies which have their own heat and light are called STARS.
Eg: Our SUN is a star.
Did you know about POLE STAR?
A Pole Star is a star which is directly above the north axis of any planetary system.
On Earth, the star to which the north pole is directly pointing is POLARIS and the pole star of Earth changes over time.
CONSTELLATIONS
Constellations are groups of stars seen as forming a figure or design in the sky.
Ursa Major or Big Bear is one such constellation.
One of the most easily recognisable constellation is the Saptarishi (Sapta - seven, rishi - sages).
Do you know why our solar system is named as
SOLAR SYSTEM?
SOLAR SYSTEM?
.gif)
Because ‘Sol’ in Roman mythology is the ‘Sun God’. ‘Solar’ means ‘related to the sun’. The family of the sun is, therefore, called the solar system.
.gif)
THE SUN
- The sun is in the centre of the solar system.
- It is huge and made up of extremely hot gases.
- It provides the pulling force that binds the solar system.
- The sun is the ultimate source of heat and light for the solar system.
- But that tremendous heat is not felt so much by us because despite being our nearest star, it is far away from us.
- The sun is about 150 million km away from the earth.
The bodies which don't have their own heat and light are called PLANETS.
Eg: Earth
.gif)
THE EARTH
.gif)
The Earth is not a perfect sphere, it is narrow in the poles and bulges in the equator.
This shape is called GEOID meaning earth-like shape.
- 3rd Nearest planet
- 5th largest planet
- Only planet in which life exists.
- Called a blue planet because Earth is covered by 71% of water and 29% of land.
- 78.08 per cent nitrogen
- 20.95 per cent oxygen
- 0.93 per cent argon.
Next,
THE MOON
The moon is a satellite.
.gif)
Satellites are bodies which don't have their own light and heat and are smaller than the average size of a planet.
- Our earth has only one satellite, that is, the moon.
- Its diameter is only one-quarter that of the earth.
- It is about 3,84,400 km away from us.
- The moon moves around the earth in about 27 days.
- It takes exactly the same time to complete one spin.
- As a result, only one side of the moon is visible to us on the Earth resulting in a full moon and a new moon.
- The moon doesn't have an atmosphere, so it will not support favourable conditions for life.
Finally, we came to the end of this chapter,
ASTEROIDS AND METEOROIDS
Asteroids are big rocks and are uneven in shape.
Meteoroids are very small rocks mostly near the sun. When these encounter the earth's surface they start to burn and most of them turn into dust before reaching the earth's crust.
