Astro2
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- Primeval Atmosphere
- 1st atmosphere made of gases from solar nebula
- Kuiper Belt
- disk of icey planetesiimals
- Dust Disk
-
*cold, low density
*debris left over by comets or collisions
*evidence of planetary systems - Comets-composition
- ice
- Secondary Atmosphere
-
current atmosphere
78%N 21% O2 - Asteroids
-
(between Mars and Jupiter)
*irregular cratered objects
*low density (not solid) - Pressure Waves
-
(earthquake waves)
can travel through liquid - Meteroites-IRON
- nickel, iron
- Accretion
- solid particles collide and stick to one another
- Comets-origon
-
long pd-randomly inclinded orbits
short pd- w/ in 30 degrees of the plane of the solar system - Hot Spots
- rising magnma rises through the mantle, pokes through and creates volcanoes
- Oort Cloud
- spherical cloud of icy bodies
- Relative Ages
- can tell which feature formed first, but not its age
- Comets-coma
- halo of gas and dust surrounding nucleus
- Terrestrial Planets
-
*small size, low mass
*dese, rocky solid surfaces
*heavy gas atmospheres
*slow rotators
*close to the sun - Meteor Showers
- Earth pases through trail and partilces fall toward Earth
- Differentiation
- seperation of planetary material according to density
- Terraforming Mars
-
*no magnetic field
*lava flows smoothed out Northern Hemisphere
*thick crust - Radioactive Dating
-
*mineral sample containing radioactive atoms which decay into daughter atoms
*percentage of radioactive and daughter atoms in the mineral
EARTH-4.3-4.4 billion years old
MOON-4.48 billion years
MARS- 4.5 billion years
METEORITES-4.6 billion years
SOLAR SYSTEM-4.6 billion years - Meterorites-STONY
- chards of glass
- Planetesimals
- baby planets that dont have enough gravity to hold an atmosphere
- Comets-tails
- gas and dust
- Jovian Planets
-
*large and massive
*low density, huge gaseous atmospheres
*rotate fast
*many moons
*rings - Stellar Motions
- detected through Doppler Shifts
- Ratiation Pressure
- light from the Sun exerted pressure on the particles, pushing them out of our solar system
- Midocean Rise
- location where planets are spreading apart
- Evidence of Extrasolar Planets
-
*detection of dust
*detection of stellar motions - Fission Hypothesis
- moon broke from Earth
- Side to Side Waves
- can't travel through liquid
- Highlands
- heavily cratered reigons (older)
- Protoplanets
-
*larger planetesimals
*able to hold an atmosphere
2 MODELS OF PLANET BUILDING:
*temp held constant during planet formation
*temp decreases over time - Condensation Sequence
-
*different materials condense from a gas into grains at different temperatures
*different materials condense at different distances from the Sun
CLOSE TO THE SUN- metal oxides, pure metals
FARTHER OUT-silicates and rocky material
OUTER REIGONS-ices (condense the fastest) - Maria
- lowland plains (younger)
- Planetary Developement
-
*differentiation produces a dense core, thick mantle, and low density crust
*young Earth heavily bombarded
*flood of molton lava - Earths Layers
-
1. inner core
2. liquid core
3. mantle - Condensation Hypothesis
- Earth and moon condensed from the same cloud
- Magnetic Field
- generated by moving charged particles in the core
- Large-Impact Hypothesis
- Moon formed when a planetesimal hit Earth
- Subduction Zone
- trench where one plate slides under another
- Solar Nebula Theory
-
*rotating cloud of dust and gas contracts and flattens
*forms a thin disk of gas and dust around the forming sun at the center
*planets grow in from the gas and dust int eh disk and are left behind when the dust clears - Condensation
- atoms of a gas hit dust grains and stick, adding mass to the particle
- Capture Hypothesis
- Moon formed elsewhere and was captured by Earths gravity
- Tidal Coupling
- Earth's gravity keeps same side of the moon facing earth
- Solar Wind
- a flow of atoms form the suns upper atmosphere also help push particles out of the solar system