Transcript The Formation of the Solar System

The Formation of the Solar
System
The Nebular Hypothesis
What makes up the Solar System?
• Sun
• Planets
– Inner – Mercury, Venus,
Earth, Mars
– Outer – Jupiter, Saturn,
Uranus, Neptune
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Moons (satellites)
Asteroids
Meteoroids
Dwarf planets
The Nebular Hypothesis
• The explanation for the formation of the solar
system
• The Solar System formed ~ 4.6 billion years
ago
– Evidence from:
• Meteorites (4.5-4.6 billion years old)
• Moon rocks (~4.0 billion years old)
• Earth Rocks(~3.9 billion years old)
– Sedimentary minerals ~ 4.2 by
The Nebular Hypothesis
• The Solar System
formed from a nebula
as gas and dust came
together to form the
sun and planets
The Beginning
• All stars, including our sun
come from nebula
• Nebula
– Cloud of gas and dust
– Remains of old stars that
have exploded (supernovas)
– Contain all of the natural
elements
• Egg
Eggs in nebula are where stars are
born
– Concentrated part of the
nebula where stars are born
The Big Spin
• An external force (like a
supernova) caused the
egg of the nebula to spin
counterclockwise
• Gravity
– Force that pulls two objects
towards one another
– Pulls the cloud inward
creating a flattened disc
• The Conservation of
Angular Momentum
– As the disc begins to flatten
it begins to spin faster
– Think of a ice skater – she
will go faster when she
brings her arms closer
The Disc
• 90% of the material
was in the center
• 10% of the material
was in the disc
surrounding it
SUN
Planets, comets,
Asteroids, Moons
The Formation of the Sun
• Within the center of
the disc:
– Compression and
Friction
– Temperature increase
– Sun “turns on”
• Nuclear fusion began
– Hydrogen fusion
The Formation of the Planets
• Accretion:
– Gas and dust particles in the disc condensed forming
ice and rock
– Ice and rock particles continued to collide and
combine into large planetesimals
– Planetesimals compressed and collided to form the
planets and moons
The Formation of the Planets
• Solar winds blew
excess gas toward
the outer part of the
solar system
• This is what made the
– Inner planets rocky
– Outer planets gas
What makes this a good
hypothesis?
• All of the planets travel in the same direction
(counterclockwise)
• The sun and most of the planets rotate in the
same direction (counterclockwise)
• All of the planets orbit the sun in the same plane
• Angular Momentum and Gravity are clearly
understood
• Nebula are very real and very common
– We can see stars in different phases of development
when we observe nebular through a telescope.
What makes up the solar system?
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Planets
Sun
Asteroids
Dwarf planets
Meteoriods
Moons
All of the above
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How old is the solar system?
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4.6 million years
3.8 billion years
65 million years
4.6 billion years
1 trillion years
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What is an “egg”?
1. Small part of a
nebula with
concentrated dust
and gas
2. The entire nebula
3. Part of a solar
system
4. Part of a star while it
is alive
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What is Conservation Of Angular
Momentum?
1. How stars are
formed
2. Nuclear fusion
3. Gravity pulls inward
the cloud, allowing it
to spin faster
4. A math equation in
this class
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What percentage of the spinning
disc created the sun?
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10%
50%
90%
45%
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What formed the sun?
1. Fire
2. Friction and
compression
3. Only spinning
4. The Big Bang
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What is accretion?
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Debris collecting
together and making a
larger object due to
gravity
The solar system
spinning
Same thing as nuclear
fusion
A really cool band name
\m/
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