The Earth in the Solar System | class 6th | old NCERT

Introduction:-

Look up at the night sky! You will see the moon, stars, and sometimes a bright moving object. Ever wondered what they are? Our Earth is part of a big space family that moves around the Sun. This family is called the Solar System. The Sun gives us light and heat, making life possible on Earth. Let’s learn more about our place in this vast universe!

Solar System:-

When we look at the sky at night, we see the moon, stars, and planets. But do you know what they are and how they are connected?

• The Solar System is like a big space family with the Sun at the center.
• The planets, moons, asteroids, and other celestial bodies move around the Sun in fixed paths called orbits.
• Our Earth is one of these planets.

The Sun – The Center of the Solar System

• The Sun is a huge and a hot ball of gases.
• Its gravity binds all the bodies together, keeping them in their orbits.
• It gives light and heat, making life possible on Earth.
• It is nearest star to Earth but still about 150 million km away.

Stars and Constellations:-

• Like the sun, there are millions of stars in the sky.
• Stars are big balls of fire that shine on their own.
• Some stars form patterns in the sky called constellations, like Saptarishi.
  • Saptarishi is the group of seven stars. It forms a part of Ursa Major Constellation.
    • Note:- Ursa Major is also called the Great bear. It is in the Northern sky. It helps in navigation. Furthermore, people in ancient times used this as a symbol for finding directions at night.
• The North Star or The Pole Star stays fixed and helps travelers find directions.

Planets:-

• Planets are large celestial bodies.
• They move around the Sun in fixed paths (orbit).
• They do not have their own light.
• There are eight planets in the Solar System.
  • Earth is one of the planets and the only one known to have life.
    • Earth is the third planet from the Sun.
    • Its shape is Geoid and it is the fifth largest planet.
    • It has air, water, and land, making it perfect for living beings.
• Planets are:- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

The Moon:-

• Moon is a only natural satellite of the Earth. (because it moves around the Earth)
• It shines because of the Sun’s light.
• It is about 3,84,400 km away from our mother earth.
• Moreover, Its diameter is only one-quarter that of Earth.
• It takes about 27 days to complete one orbit around Earth.
• Additionally, It changes shape every night, from a full moon to a new moon.
  • A Full Moon (Purnima) is when we see the entire moon shining brightly in the sky.
  • A New Moon (Amavasya) is when the moon is not visible at all.
• Note:- The change in shape is seen because sunlight falls on the moon differently.

Satellites – Natural and Human-Made

• A natural satellite moves around a planet, like the moon around Earth.
• And, Human-made satellites help in communication, weather study, and research.

Space Rocks:-

• Asteroids are rocky objects mostly found between Mars and Jupiter.
• Meteoroids are space rocks that sometimes fall to Earth, looking like shooting stars.

The Universe:-

• Our Solar System is part of the Milky Way Galaxy.
• The Universe has countless galaxies, making it unimaginably huge.
  • A galaxy is a huge group of stars, planets, gases, and dust held together by gravity.