Download Unit 3: Formation of the Solar System

UNIT 3: FORMATION OF THE
SOLAR SYSTEM
Mrs. Boorom
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The sun and all the planets and other bodies
that revolve around it make up the solar
system.
Planets are the primary bodies that orbit the
sun.
In the 1600s and 1700s, many scientists thought
that the sun formed first and threw off the
materials that later formed the planets.
However, in 1796, Pierre-Simon LaPlace
advanced a hypothesis called the Nebular
Hypothesis.
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Laplace’s hypothesis states that the sun and
the planets condensed at about the same
time out of a rotating cloud of gas and dust
called a nebula.
Modern scientific calculations support this
hypothesis.
THE NEBULAR HYPOTHESIS:
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Matter in the universe is gathered in clouds of
dust and gas. 5 billion years ago, gravity
increased greatly and this rotating cloud of dust
and gas formed the sun and planets.
This cloud that formed the planets is called a
solar nebula.
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The inside of this cloud became extremely hot
(10,000,000 oC)from collisions and pressure at
the center of the solar nebula. At this
temperature, hydrogen fusion began and the
sun was formed.
About 99% of the matter of the solar nebula
makes up the sun
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Small bodies from which a planet originated in
the early development of the solar system are
called planetesimals.
Some planetesimals joined together through
collisions and through the force of gravity to form
larger bodies called protoplanets.
Moons are the smaller bodies that orbit the
planets.
Protoplanets not massive enough to clear away
other objects near their orbits became the dwarf
planets.
FORMATION OF THE MOON… A COLLISION
WITH A MARS LIKE PROTOPLANET AND EARTLY
EARTH.
SOURCE; NASA
INNER PLANETS:
Mercury
 Venus
 Earth
 Mars
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INNER PLANETS
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Close to the sun
Contain large percent of heavy elements, such as
iron and nickel.
The denser materials sank to the center of
planets thus forming layers.
The inner planets are smaller, rockier, and
denser than the outer planets.
OUTER PLANETS
Jupiter
 Saturn
 Uranus
 Neptune
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Formed in the colder region
Did not lose their lighter elements, such as
hydrogen and helium ;or ice
Thus Jupiter and Saturn are called gas giants;
while Uranus and Neptune are the ice giants.
PLUTO: THE FIRST DWARF PLANET
(SINCE 2006)
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Originally the 9th planet and named in 1930
Smaller than Earth’s moon
Made of frozen gas and rock
Its orbit is very tilted.
Your turn…
On ISN page 18, use color pencils to copy
FIGURE 2 on page 750-751.
Then add your own VISUAL VOCAB or a
CONCEPT MAP of the key words from today’s
lesson.
*IF not finished in class, finish for HW!
On ISN page 18, use color pencils to copy
FIGURE 2 on page 750-751.
Then add your own VISUAL VOCAB of the key
words from today’s lesson.
*IF not finished in class, finish for HW!
`
On ISN page 18, use color pencils to copy
FIGURE 2 on page 750-751.
Then add your own VISUAL VOCAB of the key
words from today’s lesson.
*IF not finished in class, finish for HW!
On ISN page 18, use color pencils to copy
FIGURE 2 on page 750-751.
Then add your own VISUAL VOCAB of the key
words from today’s lesson.
*IF not finished in class, finish for HW!
On ISN page 18, use color pencils to copy
FIGURE 2 on page 750-751.
Then add your own VISUAL VOCAB of the key
words from today’s lesson.
*IF not finished in class, finish for HW!
FORMATION OF SOLID EARTH
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When Earth formed, its high temperature were
due to:
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Energy from collisions, compression of outer layers, and
radioactive materials.
Dense materials, such as molten iron, sank to
Earth’s center. Less dense materials were forced
to Earth’s outer layers in a process called
differentiation. This caused Earth to form
three distinct layers.
EARTH’S 3 LAYERS
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At the center is a dense core composed of iron
and nickel.
In the middle is the mantle composed of iron
and magnesium rich rock.
The outermost layer is the crust composed of
silica-rich rock and is least dense.
Earth’s surface continued to change as a result of
heat transfer.
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The original atmosphere of Earth consisted of hydrogen
and helium. The sun heated these gases so they escaped
Earth’s gravity.
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Earth’s early atmosphere continued to form when volcanic
eruptions released gases in a process called outgassing.
These volcanic eruptions occurred more frequently than
today. Volcanoes released the following gases: water
vapor, carbon dioxide, nitrogen, methane, sulfur
dioxide, and ammonia.
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The molecule that contains three oxygen atoms and collects
in Earth’s upper atmosphere is called ozone. It shields
Earth’s surface from the harmful UV (ultraviolet)
radiation of the sun.
EARTH’S PRESENT ATMOSPHERE
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Some of Earth’s early organisms, such as
cyanobacteria and early green plants, used
carbon dioxide during photosynthesis.
Oxygen: is a byproduct of photosynthesis and
was released into the atmosphere.
About 2 billion years ago, oxygen increased
greatly in the atmosphere. It is similar to the
amount found in the atmosphere today.
FORMATION OF EARTH’S
OCEANS
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Comet collisions may have contributed a
significant amount of water to Earth’s surface.
Earth’s first oceans were made of fresh water.
Over millions of years and rain water traveling
through rivers to reach the ocean created salt
water from dissolved rocks on land.
Earth’s atmosphere and surface cooled because
ocean water dissolved much of the carbon
dioxide in the atmosphere.