1. Formation of the Solar System

2. Demonstration
There are four bowls with pepper around the room. Get in a place where you can observe it.
When given the instruction, mix the water and the pepper
Record your observations

3. 1 2 3

4. Observations
Sketch and describe how the pepper is distributed in the bowl
Sketch and describe what happens when you first start mixing the water and the pepper
Sketch and describe what happens after you stop mixing the water and pepper. Be sure to mention how fast the pepper is moving near the outside of the bowl vs. the center

5. Formation of the Solar System
A hypothesis for the formation of the Solar System must answers four questions:
Why do things move in a common pattern?
Why are there two types of planets?
Why do asteroids and comets exist?
Why do exceptions to the general patterns happen?

6. Take notes on video

7. The Nebular Theory
States that the formation of the Solar System came from the collapse of a nebula
Pioneered by Immanuel Kant and Pierre-Simon Laplace
Accurately answers the four questions

8. Review: What’s in a Nebula
Dust
Metals
Minerals
Rocks
Gas
Hydrogen
Helium
Methane
Water
Ammonia

9. Patterns of Motion
Simply stated, this means everything moves around the Sun in the same way.

10. The Patterns of Motion
Gravity draws all the gas and dust together and the nebula collapses
As it collapses, it begins to spin and heat up
Particles hit each other, flattening the cloud to a disk
Mass accumulates in the center of disk, resulting in a protostar

11. The Patterns of Motion 1 2
The original cloud is large and spread out and its rotation is very slow. The cloud begins to collapse
Because of the conservation of energy, the cloud heats up as it collapses. Because of angular momentum, the cloud spins faster as it contracts. 3 4
The result is a spinning, flattened disk, with mass concentrated near the center and the temperature highest near the center
Collisions between particles flatten the cloud into a disk.

12. The Two Types of Planets
The disk consolidates to form the Sun and the planets
The two types of planets come from differences in temperature across the disk
The particles that make the rocky planets solidify at a higher temperature than the gas planets
The point where this the gas turns to liquid or ice is called the frost line

13. The Frost Line
Within the frost line, rocks and metals are solid but hydrogen compounds stay gaseous
Beyond the frost line, hydrogen compounds, rocks, and metals turn to solids
Within the solar nebula, 98% of the material is hydrogen and helium gas that doesn’t condense anywhere.

14. Planet Formation
Planets gradually form through a process called accretion
In accretion, particles of rock or ice collide with each other and stick together
Eventually accretion creates seeds of planets called planetesimals
Planetesimals join together to make the planets

15. Accretion

16. Planet Formation
Inside the frost line, the planetesimals do not create enough gravitational pull to attract gas
This is because the gas has too much energy
Outside the frost line, the planetesimals do attract gas
This is because the gas no longer has as much energy and turned into a liquid or solid

17. Planet Formation

18. Comets and Asteroids
Comets and asteroids come from the leftovers of planetesimals that did not join planets
Asteroids come from the leftover rocky planetesimals
Comets come from the leftover icy planetesimals

19. Exceptions to the Pattern
Planets create enough gravitational pull to capture moons
The gas that wasn’t taken in by planets was pushed out of the solar system by solar wind
Planetesimals hitting planets could knock planets onto their sides

20. Check Your Understanding
What did the pepper represent in the activity?
What part of the formation of the Solar System did observation 3 represent?
How would you describe the formation of the Solar System using the activity?
How does this activity and the formation of the Solar System differ?

21. When Materials Solidify
Metals
Rock
Hydrogen Compounds
Hydrogen and Helium Gas
Examples
Iron, Nickel, Aluminum
Various Minerals
Water (H2O), Methane (CH4), Ammonia (NH3)
Hydrogen, Helium
Typical Condensation Temperature
1,900 ºF –2,400 ºF
440 ºF –1,900 ºF
-190 ºF
do not condense in nebula
Relative Abundance (by mass)
0.20%
0.40%
1.40%
98%