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M+P-Quiz 3

Term Definition
Features of SS relating to its origin (5) -Planar (disc-like) form
-rotate in prograde motion
-inner planets (terrestial)
-outer planets (jovian)
-Kuiper Belt
Planar (disc-like) form The SS is disc-shaped with all planets orbiting nearly the same plane
Prograde motion (how do planets rotate?) All planets rotate in a "prograde motion" (counterclockwise orbital motion of planets)
Inner Planets (real name, description, what planets?) -TERRESTIAL
-small, dense, little or no atmosphere
-Mercury, Venus, Earth, and Mars
Outer planets (real name, description, what planets?) -JOVIAN
-large, low density, thick atmospheres, has rings
-Jupiter, Saturn, Uranus, Neptune
Kuiper Belt (where? what?) -orbit the Sun beyond Neptune
– composed of small, icy bodies called Kuiper Belt Objects
Catastrophic Hypothesis (def & example) -Explanation for natural processes that depend on dramatic and unlikely events
Ex- collision of two stars to produce our solar system
Solar Nebula Theory (def & why is this accepted) -Supposes that planets form in rotating disks of gas and dust around young stars
-Astronomers accept this evidence because it is more extensive and mathematically sophisticated version of Nebular hypothesis
Closed system concept -Sample that you are dating that hasn't been dated or changed since magma cooled
-working of science
cross-checking of ratios -way of checking closed system
-predictive check
Based on radiometric dating, what evidence supports a 4.6 billion-year age for our SS? Meteorites are the primary source
Factors involved with formation of inner and outer planets (3) 1) temperature decreases from solar disk to solar edge
2) chemical fractionation of Solar Disk by Solar Wind
3) powerful gravity of the growing outer planets
Origin of heavy elements "big bang" event produced Hydrogen and Helium
Where did heavier element come from? (2 examples) 1) occurs from supernovi–> explosions are rather big
2) "the metals" – generated from nuclear reactions that occurred in cores of subsequent stars
Process of planetary accretion "snowball effect"
-sticking together of solid particles
-more matter you concentrate, the more matter you produce
condensation–> accretion–> planetisimals
What is meant by Late Heavy Bombardment? What celestial object best displays the effects of bombardment? – end of planetary accretion
-period of intense meteorite impacts early in the formation of planets
-seen on the moon
Density Segregation (Density Differentiation) -Separation of material according to density
– After a planet melted, the heavy metals such as iron and nickel would settle to the core
What key Earth interior zones were produced by this process? Metal core and low-density crust
Kepler Probe -used transit method to examine 150,000 stars
-As of July 2014, there were almost a thousand confirmed exoplanets ranging in size larger than Jupiter to smaller than Earth
Importance of Stellar wobble for locating exoplanets -stars in galaxy have a certain wobble
-how first exoplanets were located –critical tool to look at stars in the milky way
-earth would wobble and not remain fixed, this is the same for exoplanets
Terrestrial planets composed of density-related layers (5) 1) Core
3) Crust
4) Hydrosphere
5) Atmosphere
Core Iron and nickel
-specific gravity=10
Mantle Silicate (metals with oxygen), like "plastic"
-specific gravity=5
Crust Lighter silicates, sentiments, brittle
-specific gravity= 3.8
Hydrosphere and Atmosphere Hyd- oceans
Atm- light gasses
4 Stages of Planetary Development 1) Differentiation
2) Cratering
3) Basic Flooding
4) Slow surface evolution
Differentiation heat source= radioactive heat from isotopic decay, plus bombardment associated with planetary accretion
Cratering initial hard surface needed to preserve craters; fall-off in big impactors
Basic Flooding Flooding by molten rock and later by water can fill lowlands
Slow surface evolution continues due to geological processes, including erosion
Earth's interior: How do we know that Earth has a core, mantle, and crust? – (Geomagnetic Evidence) 1) evidence of iron and nickel core
2) density of surface rocks are too low to account for planet
3) rocks that fall from space (meteorite)
-main line of evidence to assess what is in middle of planets (iron)
Seismic waves made by earthquakes and detected by seismographs
-Geoscientists use arrival times of reflected and refracted seismic waves to construct a model of Earth's interior
Pressure (P) waves can travel through a liquid
Shear (S) waves can't travel through liquid
–> can't pass through Earth's core
—–> evidence that a significant portion of Earth's core is liquid
Why does Earth have such a big magnetic field? -direct result of rapid rotation and its molten metallic core
Earth's magnetic field: -Convection within liquid core (Fe-Ni conductivity)= dynamo effect
-process of the rotation of convecting, conducting liquid generates magnetic field
Bow shock Solar winds are diverted along field lines
Charged particles enter ionized zone…
(what happens? what 3 things are produced?
–> energy is lost when radiation leaks
–> energy that is lost is converted to visible light
-this produces Van Allen belts of radiation
-Aurora Borealis and Aurora Austrialis
Aurora Borealis vs. Aurora Austrialis AB-Northern Hemisphere
AA-Southern Hemisphere
Plate Tectonics -crust divided into moving sections
-heat flowing upward from interior drives plate tectonics
-global pattern of lithosphere generation and destruction (birth-death of oceans and collision of continents)
Lithosphere solid topmost mantle capped by crust (=rigid rock)
Asthenosphere "weak sphere"
-underlain by semi-liquid zone
-separates lithosphere from rigid deeper mantle
Plate Divergence (rifting) creates basalt-floored , ocean basins at ocean ridges
Seafloor Spreading continued rifting causes conveyor belt-type spreading of the ocean floor as seen in the modern Atlantic
primeval atmosphere earliest atmosphere of accreting Earth : low mass, high temp
-rich in Hydrogen, Helium, and hydrogen compounds from solar nebula
-(this is why we are interested in getting samples from comets)
secondary atmosphere -internal heat of early Earth produces primitive atmosphere through volcanic outgassing of reducing gasses
-Carbon Dioxide, Hydrogen, Nitrogen compounds, Sulfur compounds
-generated atmosphere as now understood
anoxic atmosphere–>biogenic photosynthesis a.a.-early atmosphere
b.p.- build-up of oxygen in atmosphere and oceans
anaerboic bacteria -earliest organisms
-living in the absence of oxygen
-oxygen would have been poisonous to these life forms