The document summarizes the formation of the solar system based on the nebular hypothesis. It describes how: 1) A giant cloud of dust and gas gravitationally contracted to form a solar nebula. 2) Condensation occurred within the solar nebula, with different materials condensing at different temperatures. 3) Accretion and differentiation led to the formation of planetesimals and eventually planets, with terrestrial planets like Earth forming near the sun and gas giants like Jupiter forming farther out where temperatures allowed hydrogen and helium to condense.

1. Solar System Formation
LACC: § 6.2, 6.3, 6.4
• Gravitational Contraction of a giant cloud of
dust and gas
• Condensation
• Accretion w/ Differentiation
An attempt to answer the “big question”: how did
we get here?
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2. Nebular Hypothesis
2:15
http://www.youtube.com/watch?v=qfdDWdZcpOw
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3. Gravitational Contraction
What started out
as a cloud of dust and
gas light-years across,
gravitationally
collapsed to a solar
nebula thousands of
AU across.
(1 ly = 63,240 AU)
http://eps.berkeley.edu/cig/depaolo/eps102/PPT5_Condensation_Accretion.html
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4. Gravitational Contraction
What started out as a cloud of dust and gas light-years across,
gravitationally collapsed to a solar nebula thousands of AU across.
(1 ly = 63,240 AU)
http://www.jwst.nasa.gov/birth.html
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5. Solar Nebula:
Composition
Note the typical
condensation
temperatures.
http://woodahl.physics.iupui.edu/
Astro100/08-T01.jpg
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6. Protoplanetary Disks
Evidence for the Nebular
Hypothesis: process is
observed happening
around other stars
http://burro.astr.cwru.edu/denise/Spring03/Mar27/Mar27.htm
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7. Condensation then Accretion
http://eps.berkeley.edu/cig/depaolo/eps102/PPT5_Condensation_Accretion.html
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8. The Frost Line and
Condensation
http://boojum.as.arizona.edu/~jill/NS102_2006/Lectures/Lecture6/lecture6.html
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9. Accretion
http://eps.berkeley.edu/cig/depaolo/eps102/PPT5_Condensation_Accretion.html
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10. Solar System Formation
LACC: § 6.2, 6.3, 6.4
• Gravitational Contraction of a giant cloud of
dust and gas: Solar Nebula--98% H, He;
flattens into a spinning disc
• Condensation: the colder the temperature, the
greater the number and types of compounds
that will condense
• Accretion w/ Differentiation: formation of
planetesimals, many of which will combine to
form planets
An attempt to answer the “big question”: how did
we get here?
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11. Formation of the Planets
LACC: § 6.2, 6.3, 6.4
• Know the difference between terrestrial and
gas giant planet: orbital distance, mass, size,
density, composition, no. or moons
• Understand why there are terrestrial and gas
giant planets: the frost line
• Understand the roles of the initial volatile
molecules: CH4 (methane), NH3 (ammonia),
H2O (water)
An attempt to answer the “big question”: how did
we get here?
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12. Planetesimals
Formation of the Solar System- Güneş Sistemi oluşumu
1:55
http://www.youtube.com/watch?v=jhYEQgLW5NM&feature=related
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13. Making Planets
Inner Terrestrial (Earthlike) Outer Jovian (Gas Giants)
• small w/ solid surface • big balls of gas
• circular orbits w/ low • circular orbits w/ low
eccentricities and inclinations eccentricities and inclinations
• high densities (about 5x • low densities (about the same
water) as water)
• atmospheres of N2 or CO2 (or • thick atmospheres of H and
no atmosphere at all) He
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14. Low e, Low Inclination Orbits
Eccentricity Orbital Inclinations
http://physics.lakeheadu.ca/courses/Astro/2310/
PlanetGraphs/graphs.htm http://burro.astr.cwru.edu/denise/Spring03/Mar27/Mar27.htm
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15. Eccentricities
Doesn’t count
(dwarf planet)
http://burro.astr.cwru.edu/denise/Spring03/Mar27/Mar27.htm
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16. Orbital Inclinations
Doesn’t count
(dwarf planet)
http://burro.astr.cwru.edu/denise/Spring03/Mar27/Mar27.htm
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17. Condensation then Accretion
Near the sun, i.e. within the
frost line, temperatures
where higher (>150 K).
Volatile materials, hydrogen
compounds, remained
gaseous and did not
condense:
• water (H2O)
• ammonia (HN3)
• methane (CH4)
http://physics.lakeheadu.ca/courses/Astro/2310/PlanetGraphs/graphs.htm
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18. Surface Gravity and Solar uv
Solar Nebula Jovian Planets
Composition
• Greater Mass =
• 98% H, He Greater Gravity
• 1.4% CH4, NH3, H2O • They hold on to H, He
becoming gas giants
• rock 0.4%
Terrestrial Planets
• metals 0.2%
Note: Jovian planets had
• They can’t hold H, He
over three times as much • Solar uv knocks H off
material to build of CH4, NH3, H20
from--2.0% vs 0.6% leaving N2 and CO2
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19. Terrestrial Planet Geology
• Condensation Note: the smaller the planet
it, the quicker it will cool.
• Accretion w/
Differentiation • Mercury: smallest and has
solid mantle
• Cooling during heavy
bombardment • Mars: smallish and had no
significant geological
• Tectonic Plates during thin activity in 3.5 billion years
crust
• Venus: active volcanoes?
• Mantle solidifies resurfaced 0.5 billion
• Interior Cools years ago
• Earth: ongoing tectonic
activity, e.g. volcanoes
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20. LACC HW: Franknoi, Morrison, and
Wolff, Voyages Through the Universe,
3rd ed.
• Ch. 6, pp. 150-151: #3.
easily, five with a little effort.
You should be able to list three
• Ch 7: Tutorial Quizzes accessible from:
www.brookscole.com/cgi-brookscole/course_products_bc.pl?
http://
fid=M20b&product_isbn_issn=9780495017899&discipline_number=19
Must Know: 1, 4, 9, 11, 12, 15, 16, 18, 19
Important: 2, 3, 5, 10
Due at the beginning of next class period
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