(a) The difference between a planet and a star is given below:
Planet |
Star |
Some celestial bodies do not have their own heat and light. They are lit by the heat and light of the stars. These bodies are called planets. |
Some celestial bodies are very big and hot. They are made up of gasses, and they have their own heat and light. These celestial bodies are called stars. |
Examples – Earth, Mercury, etc. |
Example – Sun |
b) The Sun, the eight planets, satellites and some other celestial bodies known as meteoroids and asteroids form the solar system.
c) The planets arranged as per their distance from the Sun are – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
d) The Earth is a unique planet in the solar system because:
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Conditions favorable to support life are probably found only on the Earth.
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The Earth is neither too hot nor too cold. It has water and air, which are essential for our survival.
e) We always see only one side of the moon because the moon moves around the Earth in about 27 days, and it takes exactly the same time to complete one spin.
f) Millions of galaxies together form the universe. A galaxy is a huge system of billions of stars and clouds of dust and gasses.