The document discusses the origins and evolution of the universe, our solar system, and some key astronomical concepts. It describes how the universe began as a tiny, hot, dense point around 15 billion years ago (the Big Bang theory) and has expanded and cooled over time, forming galaxies and stars. It explains that planets in our solar system formed from a rotating disc of dust and gases around the sun. Some key facts provided include the chemical composition of the sun, the order and periods of revolution of planets, and that the moon likely formed from a collision between Earth and a Mars-sized object early in their formations.

2.  Propounded by aristotle
 Supported by ptolemy in 140 A.D.

5.  PROPOUNPED BY Fred Hoyle ,Bondi And Gold
 DENSITY OF MATTER CONSTANT OVER TIME
EVOUTIONARY STATE THEORY
 DENSITY OF MATTER DECREASES OVER
TIME

7.  15 MILLION YEARS AGO ,
 Tiny ball -10^-43 sec ,infinite temperature
expands in a short time in to a shape of
grape fruit.
 Year losts -temp.decreases. To form a galaxy
this is known as big bang theory .

9.  Near by planet gravitational force –takes the
gases and dust from clouds –
 Dust and gases come out join together form like
a disc .this disc starts to rotate .
 Day by day discs rotates very faster
 Because of faster rotation more ,it takes the
dust like materials from outside .
 Because of this center region become very hot
and form like a proto star
 After millions of years ,expansion & compression
takes place .
 Because of this remaining gases and dust blasted
away to form stars.

10.  millions and millions of galaxies is known as
universe
 Milky way is one of the galaxy in the universe
.
 Part of milky way galaxy –solar system (sun &
planets )

12.  Mixture of gases.
 92%-hydrogen,7.8% helium ,0.2% other gases.
 Temp. on the surface on sun is 6000 celsius
 Temp. on the center of the sun is 15 000,000
degree celsius .

13.  Fusion takes place in the center of the sun.
 2 Hydrogen molecules collide
helium (new nucleus)+light energy release.
 Astronomers call sun as “big fire ball”

14.  Mercury ,venus ,earth ,mars – smaller in size
– large amounts of rocks –smaller amounts of
gas – rocky planets .
 Jupiter ,saturn ,uranus ,neptune –bigger in
size –small amounts of rocks – large amounts
of gases -gaseous planets

15. Planets name Period of rotation
(length of the day)
Period of
revolution(length of
the year )
Mercury 59 days 88 days
Venus 243 days (retro grade
motion ,east to west
on its axis )
225 days
Mars 24 hours ,37 min 687 days
Jupiter 9 hours 56 min 11 years 313 days
Saturn 10 hours 39 min 29 years 167 days
Earth 23 hours 56 minutes 365 days 6 hours 16
min
Uranus 17 hours 15 min 84 years 6 days
Neptune 16 hours 7 min 165 years
pluto 153 hours 18 min
(retrograde motion)
248 years

18.  Modern theories state that ‘ big spalt’ was
the reason for formation of moon.
Ie., huge mass of one third of that of the mars
collide with the earth soon after the
formation of the earth .
Period of revolution – 27 days 7 hours 43
minutes

24.  Lies parallel to the prime meridian near
aleutian islands
 Crossing this international date line east to
west makest the traveller gain the day .
 Crossing the line from west to east makes
the traveller repeat the day .