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2/3/2015
The Nebular Theory
The Nebular Theory
These answers are taken from Prentice Hall, Earth
Science.
©Copyright 2014. M. J. Krech. All rights reserved.
http://www.popsci.com/article/science/astronomerscapture-beautiful-image-distant-planetsforming?
src=SOC&dom=fb
The 6 Stages:
• Theory that states
the solar system
began as a huge
cloud of dust and gas
which later
condensed to form
the sun and planets
The 6 Stages:
1. Nebula
4. Protoplanets forming
1. Protosun forming
4. Moons forming
1. Spinning planetary disk
4. Solar system
Why does the Nebula Contract?
• Shock waves from a nearby
supernova explosion
What Happens to the Nebula?
• Begins to shrink and spin
• also begins to flatten
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And then...
• Protosun begins to take shape in the
center
• the gravitational forces begin to fuse
hydrogen into helium (fusion) and
the protosun become a star
Inner Protoplanets vs. Outer Protoplanets
• Inner protoplanets - most of their
lightweight gases are boiled away,
• Outer protoplanets - the lightweight
gases did not boil away so the appear
much larger
• Why? the heat from the nearby sun
Nebular Theory and Pluto
Why Pluto is so different from the other
outer planets?
Perhaps one of Neptune's moons
broke away (or was pushed by an
impact) because Pluto appears to be
similar to Neptune's moons
What about the “stuff”
around the protosun?
• the largest clumps surrounding the
protosun begin to form protoplanets
What happens to the smaller clumps?
• Newly formed planets begin to cool
• The smaller clumps begin to form
Moons (Protomoons)
The Asteroid Belt & Nebular Theory
• The asteroid belt
is rocklike objects,
found between
Mars and Jupiter,
that may not have
formed into a
protoplanet
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Oort Cloud
• a huge icy cloud called near the very edge of
the solar system
• astronomers think that other clumps that
did not form into planets (or moons or
asteroids)
• might be the home of Comets
The Nebular Theory* of Solar System
Formation
Interstellar Cloud (Nebula)
*It
is also called the
‘Protoplanet Theory’.
Gravitational Collapse
Protosun
Heating ⇒ Fusion
Sun
Leftover Materials
Asteroids
Protoplanetary Disk
Condensation (gas to solid)
Metal, Rocks
Gases, Ice
Accretion
Nebular
Capture
Terrestrial
Planets
Jovian
Planets
Leftover Materials
Comets
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