proto - planet or nebular hypothesispv.pequannock.org/ourpages/auto/2012/9/24/58904234... · 2012....
TRANSCRIPT
Proto - Planet or Nebular
Hypothesis• The origin of the universe and ultimately
our solar system!
-Big Bang Theory : 13-14 Billion Years Ago-
Huge Explosion Sends Materials Out into Space
*5-7 Billion Years Ago; Nebula- Dust
& Gas Cloud floated in space
-Accretion-(to grow by accumulation) due to the
pull of gravity nebula begins to come together
-Movement From Accretion Causes Swirling Motion In Cloud
-Swirling Materials Begin to Compress
& A Star Is Born @ Center
-Accretion forms Whirlpools (an eddy), continues
and later forms Planetesimals (baby planet)
-Planetesimals turn into
Protoplanets (teenager)
-Accretion continues and Planets
(adults) form
Our Solar System
-Remaining unaccreted materials
form comets, meteoroids,
& asteroids
-Entire process
goes from
disorganized gas
and dust material
to something
clear and
recognizable
• Crust- the outer solid layer. Under the
continents this layer is up to 45 mi. thick, while
under the oceans it may be as thin as 3 mi.
The average specific gravity here is between
2.7 and 3. The continents are mostly made of
the rock granite and the ocean floor is made of
the rock basalt.
• Mantle- the second layer, about 1800 mi. thick.
The top portion is solid, while the bottom is
more fluid, like ‘play-dough’. This layer’s
specific gravity is about 5 and it is made of iron,
magnesium, and silicon.
• Lithosphere- This is a further division made
up of the crust and upper mantle. From the
top of the tallest mountain to about 400 mi.
into the earth’s interior. This separation is due
to the fact that these two areas are made of
solid rocky material that seem to float on the
liquid lower mantle.
• Outer Core- Enormous pressure makes
this layer a liquid. It has a specific gravity
of 8 to 9, is made of iron and nickel, and is
1400 mi. thick.
• Inner Core- Extreme pressure makes
this layer a solid. It has a specific gravity
of 10 to 12, is 745 mi. thick and is made of
iron and nickel.
Earth Structure and Shape• Planet Earth is made of 4 different layers. Each
is separated from the other due to different
properties, like the material’s density, (amount
of material contained in a certain volume) or its
specific gravity.
• Oblate spheroid- The shape of earth is not a
perfect sphere. It is slightly flattened at the
poles and slightly bulging at the equator. Proof
exists in the fact that any object weighs
ALMOST the same anywhere on earth.
• Weight a measure of the amount of force of
gravity pulling an object toward the center of
earth. Weight will change if its distance from
the center of earth changes. Can be seen
using the unit of weight called a Newton. An
object that is 195 Newtons at the poles it will
be194 Newtons at the equator because it is
closer to the center of the earth at the poles and
farther at the equator.
194 N
195 N
7,900 mi
7,927 mi
24,860 mi
24,900 mi
DIAMETER - CIRCUMFERENCE -