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Introduction
Name-Sahil kumar
Class-VIII-A
Roll no-827
Subject-Science ppt
School-JNV jaffarpur
kalan new delhi-73

STARS AND SOLAR SYSTEM
1.THE SOLAR SYSTEM
2.THE PLANETS
3.phases of moons
4.moon and moon surface
5. the stars
6.contellations-like –great bear,orion,
leo major, pole stars .
7.ASTEROIDS AND COMETS

The sun its family of planets and other celestial bodies comprise
The solar system . There are 8 planets in this family these 8 planets
Contains the majority of the mass of solar system . These planets
Can be categorized into two groups , viz . Terrestrial planets
And gas giants .

In Hindi , mercury is known as budh . Mercury is nearest
Planet to sun . Ti is smallest planets of our solar system
Because mercury is very close to sun it very difficult to observe
It, as most of the time it is hidden in the glare of the sun .
However , it can observe just before sunrise or just at sunset,
near to the horizon . So it is visible only at place where trees
Or building do not obstruct the view of the horizon . Mercury
Has no satellite of its own .

Venus is earth ‘s nearest planetary neighbours . Its is the
brightest planets in the night sky .
Sometimes Venus appears in the eastern sky before sunrise .
Sometimes it appears in the western sky just after sunset .
Therefore it is often called a morning or an evening star ,
although it is not a star . Try to locate Venus in the night sky.
Venus has no moon or satellite of its own . Rotation of Venus
On its axis is to west while the earth rotates form west to east .

The earth is the only planets in the solar system on which life
Is known to exist . Some special environmental conditions
Are responsible for the existence and continuation of life on the
Earth . These include just the right distance from the sun , so
That it has the right temperature range , the presence of water
And suitable atmosphere and a blanket of ozone .

The next planets , the first outside the orbit of the earth is mars
It appears slight reddish and ,therefore it is also called the red
planets . Mars has two small satellites .

Jupiter is the largest planets of the solar system . It is so large
That about 1300 earth can be placed inside this giant Jupiter has
Large of satellites . It also has faint rings around it . You can
Easily recognise Jupiter as it appears quite bright in the sky .
If you observe it it with the help of telescope, you can also
See four of its large moons .

Beyond Jupiter is Saturn which appears yellowish in colour .
What makes it t he solar system is its beautiful rings are not
visible with naked eyes . You can be observe them with a small
Telescope . Saturn also has a large number of satellite .
One interesting thing about Saturn is that it is the least dense
Among all the planets . Its density is less than that of water .

Uranus is at a distance of 19.6 AU from the sun , which means;
The distance between Uranus and sun is 19.6 times the distance
Between earth and the sun . The mass of Uranus is times of
earth . Among upper planets , Uranus is a lightest planet.
The axis of Uranus is at 90 degree to its orbit . Uranus has 27
known satellites .

Neptune is at a distance of 30 AU form to the sun , which
means; the distance between the sun and the Neptune is 30
times the distance between the sun and the earth . The mass of
the Neptune 17 times that of earth . Neptune has 13 known
satellites .

The various shapes of bright part of moon as seen during a
month are called phases of moon . Let us try to understand why
phases of the moon occurs . You have studies in chapter 16
That the moon does not produce its own light , whereas the
sun and other stars do . We see the moon because the sun light
falling on its get reflected towards us . We therefore , see only
that part of the moon , form which the light of the sun is
reflected towards us .

The day on which the whole disc of the moon is visible is known
As the full moon day . Thereafter , every night the size of the
bright part of the moon appears to become thinner and thinner
On the fifteenth day of the moon is known as the new moon day
The next day only a small portion of the moon appears in the
sky . This is the crescent moon. The moon is the fascinating
object for poets and story –tellers . But when astronauts landed
On the moon , they found that the moon’s surface is dusty and
barren . There are many craters of different sizes.

You can easily identify some stars in the night sky . For this , you
should know what a particular constellations looks like and
where to look for it in the sky .
Stars emit light of there own . The sun is also a star . Why does
appears so large compared to the other stars .which appears
bigger , a football placed at a distance of 100 m. the stars are
millions of times farther away than the sun . Therefore , the
stars appears to us like points.

class_8_sun_and_solar_system.pdf

If looked at carefully , some of stars make certain shapes . In all
Civilization , these groups of stars have been given imaginary
Shapes and names . What is amazing is that their shapes and
relatives position have not changed since thousands of years
These are known as constellations .

There is a large gap in between the orbits of mars and Jupiter .
This gap is occupied by a large number of sun . These are called
asteroids can only be seen through large telescope. Comets are
also members of our solar system . They revolve around the sun
in highly elliptical orbits . However , their period of revolution
Round the sun . The tail of a comets is always dtrected aways
from the sun .

You must have heard that there are a number of artificial
satellites which are orbiting the earth . You might wonder how
artificial satellites are different form natural satellites . Artificial
satellites are made satellites . They are launched form the earth.
They revolve around the earth much closer than earth’s natural
satellites , the moon .

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class_8_sun_and_solar_system.pdf

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