Download formation of solar system nebular tx 1112 notes

9/5/2012
To describe the process that created our solar
system
To describe the order that objects in the solar system
were created and where the vast majority of the
mass created
Nebular Theory explains how the solar
system formed
Formation of our Solar System
a) After the Big Bang explosion, there was
only dust and gas left.
b) Gravitational forces started to pull the
dust and gas together to form a nebula.
As the nebula grew, gravity increased
and pulled in more gas and dust.
c) The nebula started to rotate.
rotate Increased
gravity caused the nebula to contract
or get smaller and more compact.
d) The most compacted part of the nebula
was in the center. This is where the
sun started to form 4.6 billion years
ago.
ago.
98.5% of the nebular dust and gas went to
building the sun.
sun.
What happened to the leftovers?
• Due to the power of the gravitational forces,
forces,
98.5% of the nebula formed the sun.
• The remaining 1.5% was too far from the sun to
be affected by gravity. This left a clear area
between the sun and the leftovers.
leftovers.
• Planets, moon, asteroids, meteors, comets, etc.
were formed from the left over materials 0.5
billion years after the sun.
• Planets formed in the leftover area of dust of
gases in a two step process.
1. Condensation:
2. Accretion:
Condensation
• We know from studying water,
that condensation is when a
gas is changed into a liquid
because gas crosses its’
boiling point.
point.
•We see this happen as a cold
sold warms up and water
droplets form on the outside.
• The leftover gases were very
far away from the sun, causing
cold temperatures, and forcing
them to condense and form
liquids.
liquids
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9/5/2012
(d) Different materials will condense at
different temperatures:
Rocky & metallic materials (iron,
magnesium, and silicon) have low boiling
points. The change first, under high
temperatures because they are the
closest to the sun. Eventually, the liquids
will change into solids.
Light materials (hydrogen and helium)
have very low boiling points. They will not
change because it does not get cold
enough. They are the farthest from the
sun.
(e)Gravitational forces will compress the
solid & liquid materials to form an early
planet that is called:
Planetesimal, planetoid, or a protoplanet
Accretion
• Gravitational
forces develop in
the protoplanets,
which will start to
pull in left over
dust and gas
• This process is
called accretion
or “clearing your
neighborhood.”
• Protoplanets
grow by
accretion.
Accretion stops when there is
no more dust or gas in the
orbit.
Once accretion is complete, the
protoplanet becomes a planet.
The birth of a solar system…
1. Gravitational forces form a
nebula and it starts rotating
2. Sun forms in the middle of
nebula
3. Condensation: Leftover
gases turn into liquids,
protoplanets start to form
4. Accretion: Gravity develops
in protoplanets, adding leftover
dust in the orbit
5. Planets form when the orbital
path is clear of dirt!
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