Transcript Document

Key Ideas
Earth science is the study of:
Geology – study of Earth’s surface
and interior (minerals & rocks)
Astronomy – study of the universe
& Earth’s place in the Universe
Meteorology – study of the Earth’s
atmosphere and weather
Oceanography – study of the ocean
(waves/currents/shorelines – NOT life in
the oceans, that’s marine biology)
Origins of the Earth
Protoplanet Hypothesis – an educated guess about
the origin of the Earth & Solar System based on 6
facts
•all planets revolve around the sun in the same
direction (counter clockwise (CCW) looking
from above)
•the orbits (paths) of planets are nearly
circular
•Most of the orbits are in nearly the same flat
surface (plane)
Origins of the Earth
Protoplanet Hypothesis (continued)
•the sun rotates on its axis in almost the same
plane and direction that the planets revolve
(CCW)
•most planets rotate in the same direction as
the sun (CCW)
•most planets have moons, and their moons
revolve around the planets in the same
direction planets revolve around the sun
(CCW)
What the Protoplanet Hypothesis States
• Great dust/gas cloud 5 billion
years ago rotated in space
• Force of gravity pulled the
rotating dust & gas towards the
center
• The cloud shrank and spun
faster
What the Protoplanet
Hypothesis States (cont’d)
• Compression (squeezing)
caused friction & heat between
the molecules
• This heat caused Hydrogen
molecules to “mush” together
(Nuclear Fusion)
• This formed the sun, then the
remaining dust/gas eventually
OK, so that’s how the solar system
formed…but how did the Earth
become what it is today?
The answer
is…
Heat and
density
differences
Layers of
the Earth
Inner Core –
Earth’s center
made of solid iron
& nickel
Outer Core – layer
of liquid iron &
nickel
Mantle – thick
layer of dense
rocks
Crust – uppermost
layer of less dense
rocks (it’s thickest
below mountains)