Transcript Formation, Size and Shape of the Earth

The Formation, Size, Shape and Layers
of the Earth
DEFINITIONS, EXPLANATIONS
AND PICTURES
Condense and Converge
 Condense: To become more compact
 Converge: To come together
Steps: Formation of the
Solar System
1. Large, cold cloud of dust and
gas condenses- typically in a
nebula
2. The cloud spins, heating the
material and dividing the cloud
into a cold disk of rock and ice
surrounded by hotter gas
Formation Continued
3. Fusion first occurs in the new
star (the Sun) and little planets
form
4.Over time, nearly all of the
original material becomes a
part of the star and its orbiting
planets
Formation of the Solar System
Fusion
 The coming together of certain
elements (in the case of the sun;
hydrogen) that result in helium and
the release of large amounts of
energy.
Earth’s Interior
 The heated materials that formed the Earth
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

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sorted out by density
Inner core: Composed of solid iron and nickel
(solid due to intense pressure)
Outer core: Composed of liquid iron and
nickel.
Mantle: The thickest layer of Earth,
composed of iron, silicon, and magnesium.
The mantle is a solid that can act like a liquid
Crust: Thin, rigid layer of lighter rocks.
Includes Earth’s surface
Smooth Oblate Spheroid
 The Earth has a polar axis that is shorter
than the diameter of the equatorial circle,
therefore, the Earth bulges at the middle.
 Even with mountains like Everest, the
Earth is relatively very smooth
 Good models of Earth’s true appearance
are billiard balls, marbles, and ping pong
balls
Size and Shape of the Earth
(do not write)
 The total surface area of the Earth is
about 510 million square kilometers,
which is equivalent to about 55
continental United States
Percentages
 29% of Earth’s surface is dry land
 71% is covered by water
 The percentage covered by water
is slowly increasing as polar ice
melts
Axis and Orbit
 Axis: Imaginary straight line
through Earth between the
North and South Pole, tilted at
23.5 degrees
Kepler’s First Law
Each planet orbits the
Sun in a shape called
an ellipse
 Ellipse: An oval shape that is
centered on two points
(foci) or a single point (in the
case of a circle)
Orbit
 The path of a celestial object or an
artificial satellite as it revolves
around another object
FYI-DO NOT WRITE! Did you
know we’re spinning right
now?
 The Earth rotates at 1000 mph at the
equator
 The Earth rotates at about 700-900 mph
here
 The Earth is also revolving around the sun
at 67,000 mph
 Earth's Rotation
 Earth's Revolution
Rotation
 The Earth makes one complete turn
every 24 hours (that’s 360 degrees)
 Earth rotates at 15 degrees of
longitude per hour
 Earth rotates counterclockwise in the
Northern Hemisphere
 Rotation causes the sun to appear to
rise in the east and set in the west
Evidence of Rotation
 Foucault Pendulum: (DO NOT WRITE)
a ball and wire is suspended and set
into motion along a meridian. The
pendulum will line up with different
markings on the ground basically
showing that the Earth is moving
underneath the wire and ball)
 Foucault's Pendulum
More evidence
 Coriolis Effect: The curving of winds to
the right in the Northern Hemisphere
caused by Earth’s rotation
 Without rotation, winds would blow
straight from areas of high pressure to
areas of low pressure
 If you launch a rocket and do not account
for the Earth rotating underneath the
rocket, you will miss your target
Coriolis Effect Example
(Do not write)
 If you flush a toilet in the Northern
Hemisphere, the water will swirl to the left
(counterclockwise). If you flush a toilet in
the Southern Hemisphere, the water will
swirl to the right (clockwise)… Take a look
the next time you visit the loo!
Revolution
 Revolution: The orbital movement of an
object around another object
 The Earth revolves 1 degree per day
 The Earth revolves once around the sun
every 365.25 days
Proofs of Revolution
 Proofs:
 Parallax: Apparent shift of objects in the
sky at different times of year
 The seasons (DO NOT WRITE.. JUST FYI- If
we did not revolve, the Earth would not
vary in tilting towards and away from the
sun, meaning that seasons would not exist
->Side note: We’re actually 3 million miles
closer to the Sun in January than in July!!!)