Stars and Solar System, Class 8th Notes

THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE PATTERN

Q.1 Fill in Blanks

i. Universe ii. Meteorite iii. Planets

iv. Moon v. Pluto vi. Comet

vii. Core viii. Constillation

Q.2 True or False

i. False    ii. True     iii. False iv. False

v. False     vi. False vii. False    viii. False

Q.3

I. What is universe? Name six different kinds of heavenly bodies found in universe.

Ans: Universe is vast space which consists of stars, planets and everything else.

The Universe consists of Stars, Planets, Satallites, Asteroids, Comets, Meteors etc.

II. With the reference to the average distance from the sun, State:(a) the serial number of the planet earth (b) the average distance of the earth from the sun(c)the time in which the sunlight reaches the earth?

Ans: A. The Earth is third planet away from sun.

B. The Earth is 150 million Kilometers away from sun.

C. It takes 8 minutes for Sunlight to reach earth.

III.
a. Name the natural satallite of earth?
Ans. Moon.

b. In how many days, it completes one revolution around earth?
Ans. 28 days Approximately.

c. In how many days, it completes one rotation around its axis?

Ans. 28 days Approximately

d. How does its gravity compare with earth?

Ans. One- Sixth

e. What is maximum and minimim temperature on moon?

Ans. Max tempt is 110 C, Minimim tempt is    -150 C

IV. What do you understand by the terms New moon and Full Moon?

Ans.
New moon: When the moon is between earth and the sun, It is dark and Invisible, This is called as New Moon

Full Moon: When the earth is between sun and moon, the moon is glowing and visible. This is called Full Moon.

V.
a. Define Solar system?
Ans. The Sun and the Planets, comets, Moons, Asteroids, Satallites togather form solar system.

b. Name all planets in order?

Ans; The Planets in order are:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

VI.
a. How many moons does mars have?

Ans. Mars has two moons

b. What is the name of these moons?

Ans. The moons of mars are named as phobos and Deimos.

VII. What is comet? Why do comets have long tails while approaching Sun.

Ans. Comets are star like objects with very long tail. They revolve around the sum in eliptical orbits at high speeds.

When the comet approaches the sun, the ice, gases and dust in it changes into gaseous form which appear in form of tail.

VII. What is star? What makes star give up vast amount of energy.

Ans. Star is ball of gases which produce huge amount of heat and light.

The star gives energy because of Nuclear fusion where two hydrogen atoms fuse to form helium.

IX.
a. How are meteors different from stars?

ans: Meteors are part of comets which enter atmosphere and burn with flash because of atmospheric friction.

Star is huge gaint ball of fire which gives energy to whole solar system.

b. How are meteors different from meteorites?

Ans: Meteors are part of comets which enter atmosphere and burn with flash in sky because of atmospheric friction.

Meteorite is a meteor which fails to burn in sky and reaches earths surface.