Formation of the Solar SystemFormation of the Solar System

DemonstrationDemonstration

There are four bowls with pepper around There are four bowls with pepper around the room. Get in a place where you can the room. Get in a place where you can observe it.observe it.

When given the instruction, mix the water When given the instruction, mix the water and the pepperand the pepper

Record your observationsRecord your observations

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ObservationsObservations

1.1. Sketch and describe how the pepper is Sketch and describe how the pepper is distributed in the bowldistributed in the bowl

2.2. Sketch and describe what happens when Sketch and describe what happens when you first start mixing the water and the you first start mixing the water and the pepperpepper

3.3. Sketch and describe what happens after Sketch and describe what happens after you stop mixing the water and pepper. you stop mixing the water and pepper. Be sure to mention how fast the pepper Be sure to mention how fast the pepper is moving near the outside of the bowl is moving near the outside of the bowl vs. the centervs. the center

Formation of the Solar SystemFormation of the Solar System

A hypothesis for the formation of the Solar A hypothesis for the formation of the Solar System must answers four questions:System must answers four questions:

1.1. Why do things move in a common pattern?Why do things move in a common pattern?

2.2. Why are there two types of planets?Why are there two types of planets?

3.3. Why do asteroids and comets exist?Why do asteroids and comets exist?

4.4. Why do exceptions to the general patterns Why do exceptions to the general patterns happen?happen?

Take notes on videoTake notes on video

The Nebular TheoryThe Nebular Theory

States that the formation of the Solar States that the formation of the Solar System came from the collapse of a System came from the collapse of a nebulanebula

Pioneered by Immanuel Kant and Pierre-Pioneered by Immanuel Kant and Pierre-Simon LaplaceSimon Laplace

Accurately answers the four questionsAccurately answers the four questions

Review: What’s in a NebulaReview: What’s in a Nebula

DustDustMetalsMetalsMineralsMineralsRocksRocks

GasGasHydrogenHydrogenHeliumHeliumMethaneMethaneWaterWaterAmmoniaAmmonia

Patterns of MotionPatterns of Motion

Simply stated, this means everything moves Simply stated, this means everything moves around the Sun in the same way.around the Sun in the same way.

The Patterns of MotionThe Patterns of Motion

Gravity draws all the gas and dust Gravity draws all the gas and dust together and the nebula collapsestogether and the nebula collapses

As it collapses, it begins to spin and heat As it collapses, it begins to spin and heat upup

Particles hit each other, flattening the Particles hit each other, flattening the cloud to a diskcloud to a disk

Mass accumulates in the center of disk, Mass accumulates in the center of disk, resulting in a protostarresulting in a protostar

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.

Collisions between particles flatten the cloud into a disk.

The result is a spinning, flattened disk, with mass concentrated near the center and the temperature highest near the center

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The Patterns of MotionThe Patterns of Motion

The Two Types of PlanetsThe Two Types of Planets

The disk consolidates to form the Sun and The disk consolidates to form the Sun and the planetsthe planets

The two types of planets come from The two types of planets come from differences in temperature across the diskdifferences in temperature across the disk

The particles that make the rocky planets The particles that make the rocky planets solidify at a higher temperature than the solidify at a higher temperature than the gas planetsgas planets

The point where this the gas turns to liquid The point where this the gas turns to liquid or ice is called the frost lineor ice is called 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.

The Frost LineThe Frost Line

Planet FormationPlanet Formation

Planets gradually form through a process Planets gradually form through a process called accretioncalled accretion

In accretion, particles of rock or ice collide In accretion, particles of rock or ice collide with each other and stick togetherwith each other and stick together

Eventually accretion creates seeds of Eventually accretion creates seeds of planets called planetesimalsplanets called planetesimals

Planetesimals join together to make the Planetesimals join together to make the planetsplanets

AccretionAccretion

Planet FormationPlanet Formation

Inside the frost line, the planetesimals do Inside the frost line, the planetesimals do not create enough gravitational pull to not create enough gravitational pull to attract gasattract gasThis is because the gas has too much energyThis is because the gas has too much energy

Outside the frost line, the planetesimals do Outside the frost line, the planetesimals do attract gasattract gasThis is because the gas no longer has as This is because the gas no longer has as

much energy and turned into a liquid or solidmuch energy and turned into a liquid or solid

Planet FormationPlanet Formation

Comets and AsteroidsComets and Asteroids

Comets and asteroids come from the Comets and asteroids come from the leftovers of planetesimals that did not join leftovers of planetesimals that did not join planetsplanets

Asteroids come from the leftover rocky Asteroids come from the leftover rocky planetesimals planetesimals

Comets come from the leftover icy Comets come from the leftover icy planetesimalsplanetesimals

Exceptions to the PatternExceptions to the Pattern

Planets create enough gravitational pull to Planets create enough gravitational pull to capture moonscapture moons

The gas that wasn’t taken in by planets The gas that wasn’t taken in by planets was pushed out of the solar system by was pushed out of the solar system by solar windsolar wind

Planetesimals hitting planets could knock Planetesimals hitting planets could knock planets onto their sidesplanets onto their sides

Check Your UnderstandingCheck Your Understanding

What did the pepper represent in the What did the pepper represent in the activity?activity?

What part of the formation of the Solar What part of the formation of the Solar System did observation 3 represent?System did observation 3 represent?

How would you describe the formation of How would you describe the formation of the Solar System using the activity?the Solar System using the activity?

How does this activity and the formation of How does this activity and the formation of the Solar System differ?the Solar System differ?

  Metals Rock Hydrogen Compounds Hydrogen and Helium Gas

 

Examples Iron, Nickel, Aluminum

Various MineralsWater (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%

When Materials SolidifyWhen Materials Solidify