FORMATION OF THE SOLAR SYSTEM

Nebular Theory

Older Theory Solar nebula

Fragments spins faster and faster flattening into a disk-like feature

Formed Sun and Planets Spinning = almost perfect circle orbits Flaw

Computer models show clumps would break apart not get bigger and bigger.

needed to revise the theory

Condensation Theory

Newer Theory Interstellar Dust

From dead stars Helped to:

cool the cloud of gas making it easier to collapse the disk

speed up the process of collecting atoms to form planets

Condensation nuclei Microscopic platforms to which other atoms can

attach, forming larger balls of matter.

PLANET FORMATION

Stage 1

Accretion Dust forms condensation nuclei = clumps =

bigger clumps… By collision and sticking

End Hydrogen and Helium Millions planetesimals

Objects the size of small moons Gravitational fields large enough to effect their

neighbors

Stage 2

Collision of planetesimals due to gravity = Protoplanets Protoplanets

Build-up of matter that will become the planets Collision of planetesimals and protoplanets

Produced fragments, which some became asteroids and comets

100 million years 8 protoplanets Dozen of protomoon Protosun (protostar)

Another billion years = solar system similar to ours Extreme meteorite bombardment

DIFFERENTIATION OF THE SOLAR SYSTEM

Inner planets vs. Outer planets

Factors that influence planet formation

Temperature Hotter in the center and cooler on the outside Distance

Metallic grains = Mercury’s orbit 1 AU = silicate grains 3 or 4 AU = water ice could exist 5 AU = water vapor, ammonia, and methane

Density More dense towards the center

Gravity was affecting it all

Inner Planet

Terrestrial Planets Mercury, Venus, Earth, and Mars

Dust breaking down into atoms then reformed into new dust (grains)

Heavier elements abundant Silicon, Iron, Magnesium, Aluminum combined

with oxygen to form rocky materials Lack of lighter elements The comet bombardment of planets =

water

Outer Planets

Jovian Planets Jupiter, Saturn, Uranus, and Neptune

Cores formed under cooler conditions = low ice dense material

Accretion began soon after disk formation

Grew large enough to accrete grains and then gases from the nebula = hydrogen rich planets

Review Video

Formation of Solar System http://video.pbs.org/video/1790621534/

Questions:1. Why are asteroids so important?

• They help us understand how our solar system began

2. Where did Iron 60 come from?• Massive stars – supernova

3. What are the two ideas of how our solar system got started?

• Supernova shockwave and gentle shockwaves from a Massive star

FORCE BEHIND THE FORMATION

Gravity

Lab: Balloon on a String

Hypothesis: What direction do you think the balloons would travel in if they were released while spinning (circle, diagonal, straight line, etc…) and why?

When we are outside draw in your science journals what you see happen.

Is there anything you observed that would change your inference/hypothesis? If so what?

Lab Continue

Listen to reading What are the two forces that hold our solar

system together? Gravity and inertia

In the demo what was what? String: The Balloon: The person: The release of the balloon:

What would happen to all the planets if the Sun disappeared?

Newton’s 1st Law: Inertia

(Notes Found in your History Notes under Newton)

Inertia: the tendency for an object to keep moving in the same direction and speed unless acted upon by an outside force.

More mass = greater inertia and the more force is needed to change its motion

Gravity

Gravitational review (if time) http://www.youtube.com/watch?v=hoPKUY1

n6aA&feature=related

What object in our solar system has the largest amount of gravity? Why? Sun because it has the most mass (99.9%)

Laws of Universal Gravitation (Notes Found in your History Notes under

Newton) Gravitational force: things with mass

exerts attraction on other masses “ The mutual gravitational attraction of

the Sun and the planets, as expressed by Newton’s law of gravity, is responsible for the observed planetary orbits” (McMillan 37). The Sun pulls the planets changing the

planets forward motion into a curved path

Einstein's Theory of Relativity

“Time and space, according to Einstein's theories of relativity, are woven together, forming a four-dimensional fabric called "space-time." The mass of Earth dimples this fabric, much like a heavy person sitting in the middle of a trampoline. Gravity, says Einstein, is simply the motion of objects following the curvaceous lines of the dimple” (Dr. Tony Phillips | Credit: Science@NASA)

Trap demo http://www.youtube.com/watch?v=AAqSCuHA0j8

FUN FACTS

An inventory of the Solar System 1 sun 8 planets 5 dwarf planets 166 moons 7 asteroids more than 100 Kuiper belt objects larger than 300 km

(200 miles) in diameter 10s of thousands of smaller asteroids and Kuiper belt

objects Countless comets few km in diameter Numerous meteoroids less than 100 m across Sun makes up 99.9% of the solar systems mass

Videos

Time Travel http://www.youtube.com/watch?v=X02W

MNoHSm8&feature=related

Planet Review (if time) http://www.youtube.com/watch?v=oBp68rh

T_Sg