The document provides an overview of the solar system and related astronomical concepts. It begins by establishing that humans live on Earth, which is part of the solar system along with the sun and eight planets. It then discusses the universe, astronomy, constellations like Ursa Major and Orion, the moon's phases, planets like Mercury, Venus, Earth, Mars, and Neptune, and other bodies in the solar system such as asteroids, comets, and artificial satellites.

1. Stars and the Solar System
Submitted By: Karan Bora

2. CONTENTS
Introduction
Universe
Astronomy
Night Sky
Constellations
Moon
Planets
Solar System
Artificial Satellites

3. 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.

4. UNIVERSE
The vast unimaginable space which
encompasses most distant stars, planets
and anything else, which exists is called
universe.

5. 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.

6. 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

7. 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.).

8. 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.

9. CONSTELLATIONS (TYPES)
Constellation
s
Ursa Major Ursa Minor Orion

10. 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

11. 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.

12. 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.

13. 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.

14. MOON(Phases of Moon)

15. 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.

16. 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.

17. 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.

18. 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.

19. PLANETS-EARTH(Day and Night)

20. PLANETS-EARTH(Change of
Seasons)

21. 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.

22. 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

23. 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.

24. 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.

25. 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.

26. 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

27. 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.

28. 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.

29. 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.

30. 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

31. 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.

32. 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.