A1 05 Sol Sys Formation

Solar System FormationLACC: § 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?

1Thursday, February 25, 2010

Nebular Hypothesis

http://www.youtube.com/watch?v=qfdDWdZcpOw2:15


http://www.youtube.com/watch?v=qfdDWdZcpOw

http://www.youtube.com/watch?v=qfdDWdZcpOw

http://www.wunderground.com/cgi-bin/findweather/getForecast?query=BUR



Gravitational Contraction

http://eps.berkeley.edu/cig/depaolo/eps102/PPT5_Condensation_Accretion.html

What started outas a cloud of dust and gas light-years across, gravitationally collapsed to a solar nebula thousands of AU across.

(1 ly = 63,240 AU)




Gravitational Contraction

http://www.jwst.nasa.gov/birth.html

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://woodahl.physics.iupui.edu/Astro100/08-T01.jpg

Solar Nebula:Composition

Note the typical condensation temperatures.






Protoplanetary Disks

http://burro.astr.cwru.edu/denise/Spring03/Mar27/Mar27.htm

Evidence for the Nebular Hypothesis: process is observed happening around other stars





Condensation then Accretion




http://boojum.as.arizona.edu/~jill/NS102_2006/Lectures/Lecture6/lecture6.html

The Frost Line and Condensation




Accretion





Solar System FormationLACC: § 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



Formation of the PlanetsLACC: § 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)



Planetesimals

http://www.youtube.com/watch?v=jhYEQgLW5NM&feature=related

Formation of the Solar System- Güneş Sistemi oluşumu

1:55




http://astro.unl.edu/classaction/solar.html





























Making Planets

Inner Terrestrial (Earthlike)

• small w/ solid surface

• circular orbits w/ low eccentricities and inclinations

• high densities (about 5x water)

• atmospheres of N2 or CO2 (or no atmosphere at all)

Outer Jovian (Gas Giants)

• big balls of gas

• circular orbits w/ low eccentricities and inclinations

• low densities (about the same as water)

• thick atmospheres of H and He


Low e, Low Inclination Orbits

http://physics.lakeheadu.ca/courses/Astro/2310/PlanetGraphs/graphs.htm http://burro.astr.cwru.edu/denise/Spring03/Mar27/Mar27.htm

Eccentricity Orbital Inclinations


http://physics.lakeheadu.ca/courses/Astro/2310/PlanetGraphs/graphs.htm






Eccentricities


Doesn’t count(dwarf planet)




Orbital Inclinations


Doesn’t count(dwarf planet)




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)




Surface Gravity and Solar uvSolar Nebula Composition

• 98% H, He

• 1.4% CH4, NH3, H2O

• rock 0.4%

• metals 0.2%

Note: Jovian planets had over three times as much material to build from--2.0% vs 0.6%

Jovian Planets

• Greater Mass = Greater Gravity

• They hold on to H, He becoming gas giants

Terrestrial Planets

• They can’t hold H, He

• Solar uv knocks H off of CH4, NH3, H20 leaving N2 and CO2


Terrestrial Planet Geology• Condensation

• Accretion w/ Differentiation

• Cooling during heavy bombardment

• Tectonic Plates during thin crust

• Mantle solidifies

• Interior Cools

Note: the smaller the planet it, the quicker it will cool.

• Mercury: smallest and has solid mantle

• Mars: smallish and had no significant geological activity in 3.5 billion years

• Venus: active volcanoes? resurfaced 0.5 billion years ago

• Earth: ongoing tectonic activity, e.g. volcanoes


LACC HW: Franknoi, Morrison, and Wolff, Voyages Through the Universe,

3rd ed.

• Ch. 6, pp. 150-151: #3. You should be able to list three easily, five with a little effort.

• Ch 7: Tutorial Quizzes accessible from: http://www.brookscole.com/cgi-brookscole/course_products_bc.pl?

fid=M20b&product_isbn_issn=9780495017899&discipline_number=19 Must Know: 1, 4, 9, 11, 12, 15, 16, 18, 19Important: 2, 3, 5, 10

Due at the beginning of next class period


http://www.brookscole.com/cgi-brookscole/course_products_bc.pl?fid=M20b&product_isbn_issn=9780495017899&discipline_number=19






Education

A1 05 Sol Sys Formation