Stars and the Solar System

Submitted By: Karan Bora

CONTENTS

Introduction

Universe

Astronomy

Night Sky

Constellations

Moon

Planets

Solar System

Artificial Satellites

INTRODUCTION

We, humans live on the surface of Earth.

The earth is a planet and important part of

our solar system. Our solar system

comprises of the sun with the eight

planets. There are also other heavenly

bodies present such as comets, asteroids,

meteors, etc., about which we will study

soon.

UNIVERSE

The vast unimaginable space which

encompasses most distant stars, planets

and anything else, which exists is called

universe.

ASTRONOMY

The branch of science which deals with

the study of universe is called astronomy.

The study of astronomy involves the

methods and instruments used for the

study of the universe.

We know a lot about universe from the

information already gathered by the

astronomers.

NIGHT SKY

After sunset we see stars in the sky, if we look

through a telescope we can see many more

stars.

During day the light of the sun suppresses the

light coming from other stars and therefore they

are visible during day.

All stars are giant balls of hydrogen, including

our sun. when the hydrogen gas fuses with the

burning core of the star it emits light energy.

The stars are celestial bodies which emit heat

and light. They appear pointed because they are

very far.

NIGHT SKY (SUN)

The sun is the nearest star from the

earth.

It is a medium-order star in terms of mass

and brightness.

It appears bigger than other stars

because it is very close(150 million km.)

The next closest star is Alpha

Centauri(40678000 million km.).

CONSTELLATIONS

A group of stars which form a

recognizable pattern or shape is called a

constellation.

Astronomers have divided the whole sky

into 88 constellations.

Each constellation has been assigned a

name of an object which it closely

resembles.

CONSTELLATIONS (TYPES)

Constellations

Ursa Major Ursa Minor Orion

CONSTELLATIONS (URSA

MAJOR)

Ursa Major/Vrihat Saptarishi :

This constellation consists of seven stars

arranged in a pattern somewhat resembling a

big bear.

The Ursa Major can be linked to the

following:

a. Oversized ladle

b. Pointer stars

c. Kite

This constellation is visible in the northern part

of sky from April to September.

CONSTELLATIONS(URSA

MINOR)

Ursa Minor/Dhruva Matsaya:

Ursa Minor is also a group of seven stars

but the stars are closer and dimmer than

Ursa Major.

They form an outline of a ladle or a kite.

At the tail there is a star of average

brightness called as Pole Star(Dhruva Tara)

Ursa Minor is clearly seen in northern sky in

July summer.

CONSTELLATIONS(ORION)

Orion/Mriga:

Orion is another constellation with seven

stars. It is one of the most magnificent

constellation in the winter sky.

It looks like a hunter with his shield and

club upraised.

The seven major stars form the body of

the hunter. The head and limbs are formed

by fainter stars.

MOON

The moon is the only natural satellite of

the earth and is our nearest neighbor in

space. It’s the next brightest object after

the sun.

The surface of moon is rugged. Its made

of very large craters and very high

mountains.

Its gravitational pull is 1/6 of earth’s and it

has no atmosphere.

MOON(Phases of Moon)

PLANETS

A solid heavenly body which revolves

around the sun in a closed circular

orbit is called a planet.

There are eight planets in all,

including the earth. They have no

light of their own but appear to shine

as the light of the sun is reflected

from their surfaces.

PLANETS (Mercury)

It’s the first planet in the solar system and

is closest to the sun as its closest to the

sun it’s the hottest planet.

It has neither atmosphere nor water

because of lack of these two, no life is

possible.

Its often called the Morning or Evening

star as it is visible just before sunset or

sunrise.

PLANETS (Venus)

It’s the second planet from the sun.

Except the sun and the moon it outshines

every other heavenly body and thus is

called the brightest and the hottest planet.

It’s the brightest due to cloudy

atmosphere of carbon dioxide. This cover

reflects more than ¾ of the sunlight falling

on its surface.

This is the only planet which revolves

from east to west.

PLANETS (Earth)

Earth is the third planet from the sun. the

earth is the only planet on which life exists on

account of its correct distance from the sun

and the presence of water and air.

The earth is not a perfect sphere. The

diameter of earth is 12,800 km. and the

circumference is 40,000 km. Its atmosphere

consists of 20.9% oxygen, 78% nitrogen and

1% other gases.

The atmosphere extends to a height of 200

km from the surface of earth.

PLANETS-EARTH(Day and Night)

PLANETS-EARTH(Change of

Seasons)

PLANETS (Mars)

It’s the fourth planet from the sun and to an

unaided eye appears like a red star and

hence is also called ‘Red Planet’.

The distance of Mars from the sun is 228

x10,00,000 km. It has a diameter of 6794 km.

Its mass is 1/9 of the earth.

It has a very thin layer of atmosphere. It

rotates about its axis in 1.026 days and

revolves around the sun in 687 days.

It has two moons: Phobos and Deimos.

PLANETS (Jupiter)

It’s the fifth and the largest planet in our

solar system. Its mass being more than

that of all planets taken together.

Its distance from sun is approximately five

times the distance of the sun from the

earth.

In spite of the fact that it receives much

less light it appears to be the brightest

planet except from Venus or Mars. It is

because of its thick layer of hydrogen

which reflects most of the sunlight.

PLANETS (Saturn)

It’s the sixth planet and is roughly at a

distance that is double the distance of

Jupiter from the sun.

Saturn rotates about its axis in 0.44 days

and revolves around the sun in 29.5 years.

It is surrounded by three flat rings which

consist of rocks whose size may vary

from a speck to a few kilometers in

diameter.

PLANETS (Uranus)

It’s the seventh planet in the order of

distance from sun and is the third largest

planet in the solar system.

It was discovered by an English astronomer,

William Herschel, in 1781, with the help of a

telescope.

Its distance from sun is about twice the

distance of Saturn from the sun.

Its atmosphere is found to contain hydrogen

and methane.

PLANETS (Neptune)

It’s the eighth planet and was discovered by

Urbain Jean Joseph Leverrier, a French

astronomer in 1846. when he observed

some disturbance in the orbit of Uranus by

some other heavenly body.

However Neptune was first observed by a

German astronomer Johann Gottfried Galle

in Berlin.

It has 13 satellites out of which Triton is

quite big.

PLANETS (PLUTO)

It was till June 2006 the outermost and the

smallest planet around which revolves a

single moon. It has been deleted from the list

of planets since June 2006.

In 1930 it was discovered by C.W.

Tombaugh and was originally thought to be a

moon of Neptune. The most notable feature

of Pluto is that it cuts through the orbit of

Neptune.

Its distance from sun is 5870 million km., it

rotates in 6.9 days and revolves around the

sun in 248.7 years.

SOLAR SYSTEM

It is believed that the sun was born 5

billion years ago and is expected to emit

heat and light for another 5 billion years.

The sun along with the eight planets and

their moons constitute the solar system. In

addition to the planets and their moons,

other heavenly bodies have been found to

revolve around the sun. they are asteroids,

comets, meteors and meteorites.

SOLAR SYSTEM (Asteroids)

The small pieces of rocks or metals which

revolve around the sun, in between the

orbits of Mars and Jupiter are asteroids.

Asteroids are easily visible with a powerful

telescope. They are of varying sizes, the

largest being Ceres, which is 633 km. in

diameter.

There are about 100,000 asteroids, each

has its own orbit. The orbits are spread in

large distance forming a band.

SOLAR SYSTEM (Comets)

The bright ‘star like’ objects with a long

tail, approaching the sun in a highly

elliptical orbit are called comets.

The bright star like object is commonly

called ‘head of comet’. When it

approaches the sun the ice and gases

change to gaseous form and form the tail.

The tail always points away from the sun

because of the pressure of solar wind.

SOLAR SYSTEM (Meteors)

The bright ‘star like’ objects which appear

suddenly in the sky and then for a few

moments grow with a brilliant white flash of

light falling towards the earth and finally

disappear are finally called meteors.

It is believed meteors are the debris of

comets. A chunk of this debris when enters

the gravitational field of earth it starts falling

towards earth as it passes the atmosphere it

becomes white hot because of friction,

catches fire appearing like bright flash of

light.

SOLAR SYSTEM (Meteorites)

If a meteor is too big and fails to burn

completely in the atmosphere, then a part of

it reaches the surface of the earth. This

unburnt piece is called meteorite.

Meteorites which reach earth can be as

small as pebbles or can be as big as tonnes

of rocks and metals.

The earth receives far less meteorites as

compared to the moon because a majority of

the meteorites burn in the atmosphere of the

earth.

ARTIFICIAL SATELLITES

Artificial satellites are man-made and are

launched with the help of powerful rockets,

they revolve at a very close distance to the

earth. They are packed with many

scientific devices.

They have many practical applications

such as forecasting weather, telephone

and T.V. signals, etc..

They are used in global positioning

system for all kinds of navigation.