This document provides information about galaxies and theories of the origin of the universe. It begins with introductions from Celestial and Cosmos who are interested in astronomy and space travel. It then defines a galaxy as a large collection of stars, gas and dust held together by gravity. It provides examples of spiral galaxies like the Milky Way and Andromeda, and notes that Andromeda is approaching the Milky Way. The document also describes elliptical, lenticular, irregular and peculiar galaxies. Finally, it summarizes the Big Bang theory that the universe began as a single point and has been expanding ever since, and the steady state theory that the universe is always expanding but maintaining a constant density through continuous creation of new stars.

1. GALAXIESPrepared by: Revo D. Lazo

2. Hi! I’m Celestial.
My favorite
branch of Science
is Astronomy.
Hello! I’m Cosmos.
My goal in my life
is to travel the
outer space.

3. Objectives of My Discussion
What is Galaxy?
Other types of Galaxies..
Theory about the Origin of
The Universe.

4. Yeahhey… we are going
to travel the outer space
!! :D

5. GALAXY
- any large collection of stars that can be recognized as a distinct
physical entity
- is an enormous collection of gas, dust and billions of stars held
together by gravity.
- The closest spiral galaxy is Andromeda, a galaxy much like our
own Milky Way. It is 2.2 million light years away from us.
Andromeda is approaching our galaxy at a rate of 670,000 miles
per hour (1,078,260 kph). Five billion years from now it will
probably collide with our Milky Way galaxy.
- Galaxies are not generally found alone ; instead they are found
in clusters , and those clusters also form further group called
“super clusters”.

6. Wow!! It’s Milky
Way Galaxy our
own galaxy. Where
our Solar System
belongs.

7. WooAHH!! Andromeda Galaxy is really a giant
galaxy!!! It is 160,000 light years in diameter much
larger than our own galaxy.

8. Edwin Hubble discovered Andromeda,
allowing him to place it at more than a million
light years – much further than the most
distant reaches of the Milky Way.

9. OTHER GALAXIES
Hey Kids!! Do you want to explore more
the universe?
Me and Cosmos will take you to the
other kinds of galaxies!!! Come on get
Ready!!!

10. This is The Spiral Galaxy

11. The Elliptical Galaxy

12. The Lenticular Galaxy

13. The
Irregular
Galaxy

14. The
Peculiar
Galaxy

15. Theories about the
Origin of The
Universe
Did you
enjoy?
Now, we are going to talk
about the Theories…. Get
ready!!!

16. Big Bang Theory
- is the prevailing cosmological model for the birth of the
universe. It states that at some moment all of space was
contained in a single point from which the Universe has been
expanding ever since. Modern measurements place this
moment at approximately 13.8 billion years ago, which is thus
considered the age of the universe.

17. The Steady State
Theory
The steady-state theory is a view that the universe is always
expanding but maintaining a constant average density, matter
being continuously created to form new stars and galaxies at
the same rate that old ones become unobservable as a
consequence of their increasing distance and velocity of
recession.
Hermann Bondi Thomas Gold Sir Fred Hoyle

18. Going back home!

19. So What did you
learn in this
lesson???
Goodbye!!!