This is a PPT on The Universe ...A science PPT... Hope it helps you all,,,,......

1. The Universe is everything that exists- Stars ,
Planets , Moons , other Heavenly bodies ,
everything that exists on these heavenly
bodies , such as animals and plants on the
earth, and the vast empty space in between. It
is even impossible to even imagine its size .
The estimated diameter of the observable
universe is about 93 billion Light Years. Our
earth is not alone in the universe there are 8
more Planets along .
THE UNIVERSE

3. OUR PLANETS & STARS
Stars are huge spinning balls of hot luminous
gases. All stars give out their own light . Most
stars are made up of entirely of two gases –
Hydrogen & Helium. In the center of the stars
, hydrogen atoms combine to form helium
atoms, during this huge amount of energy is
released in the form of heat & light .
Planets are heavenly bodies that revolve
around the sun. They do not have light of
their own & reflects the light of sun to us.
They are smaller than stars .

4. SUN ( star )- The Sun is the star at the center of
the Solar System. It is almost spherical and
consists of hot plasma interwoven with
magnetic fields. It has a diameter of about
1,392,684 km, around 109 times that of Earth,
and its mass 1.989×1030 kilograms,
approximately 330,000 times the mass of
Earth . Chemically, about three quarters of
the Sun's mass consists of hydrogen, whereas
the rest is mostly helium. It is the closest star
to the earth. It is the source of almost all
energy on the earth as well as on other
planets.

5. MERCURY- Mercury is the smallest and closest to
the Sun of the eight planets in the Solar
System with an orbital period of about 88
Earth days. Seen from Earth, it appears to
move around its orbit in about 116 days,
which is much faster than any other planet. It
has no known natural satellites . As it has
almost no atmosphere to retain heat,
Mercury's surface experiences the greatest
temperature variation of all the planets,
ranging from −173 °C; −280 °F at night to 427
°C; 800 ° during the day at some equatorial
regions.

6. VENUS - Venus is the second planet from the
Sun, orbiting it every 224.7 Earth days.
It has no natural satellite. After the
Moon, it is the brightest natural object in
the night sky, reaching an apparent
magnitude of −4.6, bright enough to cast
shadows. As Venus is an inferior planet
from Earth, it never appears to venture
far from the Sun: its elongation reaches a
maximum of 47.8°.

7. EARTH- Earth, also known as the World is
the third planet from the Sun, the
densest planet in the Solar System, the
largest of the Solar System's four
terrestrial planets, and the only celestial
body known to accommodate life. The
Earth's biodiversity has evolved over
hundreds of million years, expanding
continually except when punctuated by
mass extinctions. It is home to over eight
million species. There are over 7.2 billion
humans who depend upon its biosphere
and minerals.

8. MARS- Mars is the fourth planet from the
Sun and the second smallest planet in
the Solar System, after Mercury, It is
often described as the "Red Planet"
because the iron oxide prevalent on its
surface gives it a reddish appearance.
Mars is a terrestrial planet with a thin
atmosphere, having surface features
reminiscent both of the impact craters of
the Moon and the volcanoes, valleys,
deserts, and polar ice caps of Earth.

9. JUPITER- Jupiter is the fifth planet from the Sun
and the largest planet in the Solar System. It
is a gas giant with mass one-thousandth of
that of the Sun but is two and a half times the
mass of all the other planets in the Solar
System combined. Jupiter is primarily
composed of hydrogen with a quarter of its
mass being helium, although helium only
comprises about a tenth of the number of
molecules. It may also have a rocky core of
heavier elements, but like the other gas
giants, Jupiter lacks a well-defined solid
surface.

10. SATRUN- Saturn is the sixth planet from the
Sun and the second largest planet in the
Solar System, after Jupiter. Saturn is a
gas giant with an average radius about
nine times that of Earth. Saturn's
interior is probably composed of a core of
iron, nickel and rock (silicon and oxygen
compounds), surrounded by a deep layer
of metallic hydrogen, an intermediate
layer of liquid hydrogen and liquid
helium and an outer gaseous layer.

11. URANUS- Uranus is the seventh planet from
the Sun. It has the third-largest planetary
radius and fourth-largest planetary mass
in the Solar System. Uranus is similar in
composition to Neptune, and both are of
different chemical composition to the
larger gas giants Jupiter and Saturn.
Uranus's atmosphere, although similar to
Jupiter's and Saturn's in its primary
composition of hydrogen and helium,
contains more "ices", such as water,
ammonia, and methane, along with traces
of other hydrocarbons.

12. NEPTUNE- Neptune is the eighth and farthest
planet from the Sun in the Solar System.
It is the fourth-largest planet by
diameter and the third-largest by mass.
Among the gaseous planets in the Solar
System, Neptune is the most dense.
Neptune is 17 times the mass of Earth
and is slightly more massive than its
near-twin Uranus, which is 15 times the
mass of Earth but not as dense. Neptune
orbits the Sun at an average distance of
30.1 astronomical units.

13. CONSTELLATIONS
Thousands of year ago , astronomers divided
the stars into groups, and drew imaginary
pictures around them , such as that of a
hunter or a bear. This made it easier for them
to remember the stars patterns. Such a group
of stars is called a constellation. Toady, 88
constellations are recognized by astronomers.
Some Of the constellations are given one the
next slide …

15. THE MOON
A Celestial object that revolves around a planet is
known as a Natural satellite or Moon of the
planet. Most planets have moons revolving
around them.
The Earth has only one moon . It is held in orbit
around the Earth’s gravity. It shines because it
reflects the light of the sun. It is dry and barren
with no atmosphere. Its surface is covered with
several mountains and craters. It has a diameter
of about One-Fourth that of earth and its mass is
about one-hundredth that of the earth. Its
distance from the earth is 3,84,400 Kilometers.

16. The moon completes its one revolution around
the earth in 27.3 days . It also rotates once on
its axis in the same period of time.

17. ARTIFICIAL SATELLITES
An artificial satellite is an artificial object
which has been intentionally placed into orbit,
which revolve around planets. The first
satellite was sent by USSR on 4 October 1957.
It was called Sputnik-I . Satellites are used for
a large number of purposes. Common types
include military and civilian Earth
observation satellites, communications
satellites, navigation satellites, weather
satellites, and research satellites etc.

19. WHAT IS THE BIG BANG THEORY ?
Astronomers found that the universe was
expanding. So, they put forward a theory to
explain how the universe originated. They
believe that about 15 billion years ago all thee
matter in the universe was gathered into a
single mass. Suddenly the mass exploded ,
sending particles flying in all directions.
These particles formed the galaxies with the
stars and planets. These galaxies are still
flying away other because of the explosion,
this is know as the Big Bang Theory .

20. OTHER CELESTIAL OBJECTS
Asteroids- There is a large gap between the orbits
of Mars and Jupiter. A large number of rocks
called asteroids lie in this space. The largest
asteroid is Ceres ( diameter 1003 km ).
Comets- Comets are celestial objects that revolve
around the sun in very long periods of
revolution. A comet appears like a ball of fire
with a long bright ‘tail’ as it approaches the
sun . The tail always points away from the
sun , and its size increases as it approaches
the sun. The famous Halley's comet appears

21. After every 76 years. It last appeared in 1986.
Meteors- Meteors are small objects made up
mainly of stones present in space. They
regularly enter the earth’s atmosphere. As a
meteor enters the earth’s surface at high
speed , it is heated by friction with air , and in
most cases it burns to ashes in a very short
time . As it heats up and burns it appears as a
glowing streak of light and is called shooting
star.
Meteorites- If a meteor is large , it may fall on
earths surface before being completely burnt
out. Such meteors are called meteorites.

23. THANK YOU FOR WATCHING !!
Zainul- 8a