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
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