1. Solar Nebular Theory

2. How the Universe Formed
The Solar Nebula Theory
Happened 4.6 billion years ago
A solar nebula in space was disturbed, maybe by the explosion of a nearby star (called a supernova).
Solar Nebula – the cloud of gas and dust from which the solar system formed
This explosion made waves in space which squeezed the cloud of gas and dust. 

3. Our sun formed in this protostellar disk Proto = first
Just like a dancer that spins faster as she pulls in her arms, the cloud began to spin as it collapsed and flattened into a disk.
Eventually, the cloud grew hotter and denser in the center, with a disk of gas and dust surrounding
the center was hot
 the edges were cold
Our sun formed in this protostellar disk
Proto = first
Stellar = sun; star

4. When enough material collected at the disk's center, nuclear fusion began, and our sun was born.

5. As the sun was forming, dust grains collided and stuck together in a process called accretion
Accretion is the collection of particles into a larger object by gravitationally attracting them
Some clumps got bigger, as particles and small clumps stuck to them, forming larger bodies that were kilometers across
Planetestimals (also called protoplanets)– the larger bodies from which planets formed
The protostellar disk became the protoplanetary disk  where planets formed.

6. Protostar - AKA "Baby Sun"
Area where the terrestrial planets formed
Area where the gaseous planets formed

7. Near the center of the cloud, where planets like Earth formed, only rocky material could stand the great heat. 
Terrestrial Planets – Mercury, Venus, Earth, Mars

8. Icy matter settled in the outer regions of the disk, where the giant planets like Jupiter formed.
Gas Giant Planets – Jupiter, Saturn, Uranus, Neptune

9. Stephen Hawking – Formation of the Solar System