1. The Big Bang Theory
Part I

2. The Big Bang theory The universe was created ~13.7 Billion years ago.
The universe began as a massive explosion.

3. ~ 3 minutes after big bang
All the matter and energy were condensed into an tiny and extremely dense point.

4. ~ Several hundred thousand years after Big Bang
After the explosion the matter expanded.
ATOMS formed (specifically Hydrogen and Helium.)
The early Universe was about 75% Hydrogen and 25% Helium. It is still almost the same today.

5. ~200 to 400 million years after Big Bang
1st stars and galaxies formed when the dust and the gas collapsed.

6. ~ 4.6 billion years ago
Our Solar system formed

7. Today Continuous expansion Galaxies are moving away from each other
The BIG CRUNCH
Theory which states that ,one day, the universe will STOP and begin to contract again.

8. Big Bang Timeline – Big Bang – energy Matter protons Neutrons
electrons
Atoms
Hydrogen
Helium
Stars and galaxies
Our solar system
Sun and all planets
Earth (present day)

9. what is a Galaxy?
It´s an enormous group of stars, planets, gases and dust.
It´s a gravitionally bound system.

10. Types of galaxies according to their shape:
Elliptical galaxy
Spiral galaxy
Barred spiral galaxy
Irregular galaxy

11. Our Galaxy: the Milky Way
Almost everything we see in the night sky belongs to the Milky Way.
We see the Milky Way as a faint band of light across the sky.

12. The Milky Way It’s part of the Local Group
It’s part of the Virgo Supercluster
It’s a barred spiral galaxy
We are in the Orion Arm of the galaxy.