Glossary of final -the earth and other planets ch.16

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solar system
consists of major planets, satellies, and other objects, that are gravitationally bound to the sun
planetary orbits
1. all planets orbit in the same direction around sun
2. all orbits on same plane
3. all rotate on own axis
sun is made up of:
virtually all material of the solar system
inner rocky planets (mercury, venus, earth, mars)
jovian planets
outer gaseous planets(jupiter, saturn, uranus, neptune)
the nebular hypothesis
dust gathers, forms flat disk, dense areas in disk become planetesimals which collide to start planetary accretion, mass begins to become a star, t-tauri phase starts the burning, inner planets are heated up.
inner planets characteristics
are rocky bodies that are more dense and made of materials with higher melting temperatures, silicate minerals and metals
outer planet characteristics
are gaseous bodies that are more similar to the nebular cloud in terms of composition made of materials with low melting temps or require low temps(ice and gas). lots of H and He
hadean event
early melting of the crust due to heating upon contractions of the early planet(4 bya)
heavy bombardment
meteors asteroids and small planets continually hitting the rocky surface and adding mass and heay to planet (3bya)
post-heavy bombardment
development of a stable crust upon which oceans and ice sheets may form after an atmosphere develops 3bya-present
differentation of planets
heavy, dense materials (Fe and Ni) sank to the core
lighter materials (O,Si Aa Ca Na) moved to the outer reaches (crust)
iron catastrophe
violent sinking event thought to have occurred on earth when large quantites of Fe and Ni suddenly sank to the core
a body made mainly of Fe and Ni; temp=5000C+; pressures 35000000000g/cm^2 solid in the interior part and liquid on the outer part; metallic bonds
bulk of earths mass, much denser than crust, ionic bonds prevail
a thin layer of rock, low pressure, high temp, ductile material allowing plates to move apon it.
a thin layer or shell on the outer part of the earth, lighter elements are concentrated here.
big splash theory
while still forming, a small planet hit the earth, sending mantle and bits of planet into orbit around the earth, coalesced into the moon.
big splash theory explinations
unusual composition, too large for its position, low density, large impact basin, young rocks
impact craters
basins formed by cosmic impacts
axis tilt
usually are dictated by early impacts
hadean atmosphere
any gas accumulated about an inner planet was blown away during t-tauri phase of sun inner planets only
outgassing phase
volcanoes and fissures bring molten material and gasses to surface from within the planet; H20, CO2, CH4, NH3, H2
gravitational escape phase
early planets with low graviational attraction allowed excited atoms of the upper atmosphere to escape into space(excitation energy > escape velocity)
oxygen pollution phase
on earth photosynthetic organisms that produce O caused a change in the atmosphere: oxygen build up began, today stands at about 20%
internal structure of jovian planets
solid core of rock at 40000C and under very high pressure
lower mantle of liquid metallic H
upper mantle of liquid covalent H
atmosphere of H and He
jupiters inner moon, most volcanically active planetry body in the solar system
jupiters 2nd moon, ice world, may have a liquid ocean below the ice crust, most probable home of life outside earth in this solar system
jupiters third moon, ice world with possible ocean underneath, may harbor marine life aswell
jupiters outer large moon, ice world, most heavily cratered body in the solar system
saturns largest moon, larger than mercury, cloud shrouded methane ice world with methane lakes and rivers
never visited, 250 year orbit, .3% mass of earth, chiron is moon
small, rocky, minor planets that orbit the sun, because of jupiters pull they never have same orbit twice, causes collisions
small, rock bodies, coated by ice, mainly dwell outside solar system, vaporization by sun causes gas and dust tails
long-period comets
come from the kuiper belt or Oort cloud on orbits of 1000s of years in duration.
short-period comets
orbits changed by jupiter, orbits of a few 10s to 100s of year (halleys comet 1834, 1910, 1986,2061)
meteoroids and meteors
small fragments that orbit sun,a meteoroid that enters earths atmosphere
any meteor that hits earth, iron,stony-iron, stony
carbonaceous chondrites
contain silicate minerals with a large amount of organic carbon and round objects called chondrules and amino acids

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