6.S.St.Chapater1.Geograghy.The Planet Earth and the Solar System

Chapter1.Geography

The Planet Earth and Solar System

Something to know:-

A.Tick the correct option.   

1.What do we call a huge cluster of

Billions of star?  

(C) Galaxy

2.Which one of the following is the hottest planet?

(B)Venus 

3.Which is the most distant planet from the sun?

(B) Naptune

4.The Planet which does not have any satellite is-

(A) Venus

5. Which planet has two satellites?

(D) Mars

B. Fill in the blanks.

1. The vast limitless space which includes all celestial bodies is called Universe

2. The distance between celestial bodies is measured in a unit called Light years

3. Pole star always indicates the north direction.

4. All the planets of our solar system revolve around the sun in their fixed paths called Orbit.

5. Earth is the third nearest planet to the sun.

C. Match the following:-

1. Great Bear -----------------------Constellation

2. Head of solar system-------Sun

3. A giant cloud of gases and dust------- Nebula

4. Shape of the earth---------Spherical

5. Red Planet----------Mars.

Inside questions

Q.1.What is universe?

Ans-The vast limitless space which includes all celestial bodies is called Universe.

Q.2.What is a Galaxy?

Ans-A huge cluster of billions of stars , along with the gaint collection of gas and dust ,is called a Galaxy.There are  countless stars in the space form huge clusters. One cluster may contain billions of stars. all the stars in a cluster are held together by mutual gravitational force. such a huge cluster of billions of stars, along with the giant collection of gas and dust, is called a galaxy .

Q.3.Where is our solar system located?

Ans-Our solar system is located in the Milky Way Galaxy (Akash Ganga).

Q.4.Name the things contained by Milky Way Galaxy.

Ans-The Milky Way Galaxy contains a bar across it's center region and two major arms.

Q.5.Where is the Orion Arm located?

Ans-The Orion Arm is located between the two major arms of Milky Way Galaxy.

Q.6.What are star?

Ans-Stars are self-luminous heavenly bodies. They are made up of hot gases. they generate heat and light and radiate it in the space. The number of stars is countless we do see all of them at a time. It has been said that, at one time, we can see not more than 6,000 stars. though, stars are very huge bodies, they look very far away from the earth.

Q.7.What is the function of stars?

Ans-The function of the Stars is to generate heat and light and to radiate them in the space.

Q.8.Name the unit used to measure the distance between the celestial bodies.

Ans-Light year is used to measure the distance between the celestial bodies.

Q.9.What is the light year?

Ans- The distance between celestial bodies is usually measured in a unit known as light year.

Q.10 What is the “Proxima Centauri”? And it is how much far away from us?

Ans- Some stars are so far away that the light radiated by them reaches us in millions of years. The nearest star to the earth, other than the sun, is the “Proxima Centauri”.It is about 4 [1/2] light years away from us.

Q.11.What do you know about the milky way galaxy?

Answer a faint white band, stretching across the sky, is a barred spiral galaxy. it contains a bar across its centre region and has two major arms. the orion arm is located between two major arms.

D. Answer the following questions:-

Q.1. What are celestial bodies?

 Ans The sun and, the star,the moon,the planets and other objects are called celestial bodies. All the objects which appear smaller to us are the heavenly bodies

Q.2.Why do stars, look very small in the sky?

Ans Stars look very small in the sky because they are very far away from us.

Q.3.What is Saptarishi Mandal?

Ans Saptarishi Mandal is a constellation which consists of seven star looks like a great bear.

Q.4.Name the planets which are gaseous bodies.

Ans Jupiter, Saturn are planets which are gaseous bodies.

Q.5.Which planet is closest to the Neptune?

Ans Uranus is the planet closest to Neptune

E. Answer the following questions

Q.1. Describe the formation of solar system.

Ans The sun and it's companion celestial bodies which consists of solar system. Some scientists believe that a giant cloud if gases, and dust called the Nebula appeared moving in the space about 4.6 Billions of years ago . It cooled and gained very fast rotation. The eight ball of gases of different sizes were separated from the nebula. The remaining central mass of the Nebula changed in a star known as the sun. The other eight balls changed into planets.

Q.2.State three features which make the earth a unique planet.

 Ans The three features are:-

(i) The Earth receives moderate heat and light from Sun

(ii) About two-thirds area of Earth is covered with water.

(iii) The Earth has an envelope of air around it.

Q.3.Mention three characteristics of a satellite.

 Ans  The three characteristics of satellite are :-

(i) The heavenly bodies that revolve around their respective planets.

(ii) Satellites do not have their own heat and light.

(iii) They reflect light , which they receive from the Sun.

Q.4.Give a brief description on the phases of Moon with the help of a diagram.

Ans The phases of Moon are used to determine the lunar dates and to fix the duration of lunar months and Arab countries.The Hindu and the Muslim festivals Such as Deepawali and Eid are usually fixed on the basis of lunar dates and months.

Q.5.Write a short note on the other celestial bodies (asteroids, meteoroids and comets in the solar system).

Ans. Asteroids- are rocky,space objects that orbit our sun.These can be a few feet wide to several hundred miles wide.

    Meteroids- are little chunks of rock debris in space.They become meteors or shooting stars when they fall through the earth's atmosphere.

    Comets- Comets are the small bodies with a head and long luminous tail.They are made up of dust and frozen gases.

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