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161 Cards in this Set
- Front
- Back
Sunspot |
Relatively dark spot on the sun that contains intense magnetic fields.
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Granulation |
Hot magma rising and falling, then cools. Caused by convection |
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Convection
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occurs when hot fluid rises and cold fluid sinks
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Supergranules
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: very large convective features in the sun's surface
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Filtergram
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: a photograph (usually of the sun) taken in the light of a specific region of the spectrum
(Example: H∝ filtergram) |
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Spicule
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: a small, flame–like projection in the chromosphere on the sun
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Coronagraphs
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: a telescope designed to photograph the inner corona of the sun
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Magnetic Carpet
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: the network of small magnetic loops that covers the solar system
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Solar Wind
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: rapidly moving atoms and ions that escape from the solar corona and blow outward through the solar system
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Helioseismology
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: the study of the interior of the sun by analysis of its modes of vibration
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Weak Force
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–1 of the 4 forces of nature
–responsible for some forms of radioactive decay |
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Strong Force
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–1 of the 4 forces of nature
– binds protons and neutrons together in atomic nuclei |
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Nuclear Fission
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: reactions that BREAK the nuclei of atoms into fragments
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Nuclear Fusion
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: reactions that JOIN the nuclei of atoms to form more massive nuclei
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Proton–Proton Chain
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: a series of 3 nuclear reactions that builds a helium atom by adding together protons.
–The main energy sources is in the Sun |
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Deuterium
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: an isotope of hydrogen in which the nucleus contains a proton and neutron
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Positron
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: the antiparticle of the electron
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Neutrino
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: a neutral, massless atomic particle that travels at or nearly at the speed of light
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Coulomb Barrier
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: the electrostatic force of repulsion between bodies of like charge
–Commonly applied to atomic nuclei |
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Radiative Zone
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: the region inside a star where energy is carried outward as photons
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Convective Zone
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: the region inside a star where energy is carried outward as rising hot gas and sinking cool gas
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Maunder Butterfly Diagram
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: a graph showing the latitude of sunspots vs. time
–First plotted by W.W. Maunder in 1904 |
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Zeeman Effect
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: the splitting of spectral lines into multiple components when the atoms are in a magnetic field
–Used by astronomers to measure the magnetic fields on the sun |
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Maunder Minimum
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–Historical records show that there were very few sunspots from about 1645–1715.
*This phenomenon is known as the "Maunder minimum". Coincides w/ a period called the "little ice age", a period of unusually cool weather in Europe and N. America |
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Dynamo effect
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: the process by which a rotating, convecting body of conducting matter, such as Earth's core, can generate a magnetic field
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Differential rotation
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: the rotation of a body in which different parts of the body have different periods of rotation.
–This occurs in the sun, the Jovian planets, and the disk of the galaxy |
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Babcock model
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: a model of the sun's magnetic cycle in which the differential rotation of the sun winds up and tangles the solar magnetic field in a 22–year cycle.
–This is thought to be responsible for the 11–year sunspot cycle |
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Prominence
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–Eruption on the solar surface
–Visible during total solar eclipse |
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Filaments
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–a solar prominence
–seen from above –silhouetted against the bright photosphere |
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Flares
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a violent eruption on the sun's surface
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Reconnection
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: on the sun, the merging of magnetic fields to release energy in the forms of flares
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Aurora
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:colorful light caused by charged particles from the sun interacting with our atmosphere to excite atoms and emit photons
–gases emit visible light |
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Coronal Mass Ejections (CMEs)
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: matter ejected from the sun's corona in powerful surges guided by magnetic fields
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Coronal Holes
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* They are sources of the solar wind
* Related to the sun's magnetic field * 20% of the surface |
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Stellar Parallax (p)
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: a measure of stellar distance
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Parsec (pc)
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: the distance to a hypothetical star whose parallax is 1 second of arc.
: 1 pc= 206,265 AU= 3.26 ly |
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Flux
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: a measure of the flow of energy through a surface. Usually applied to light.
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Absolute Visual Magnitude (Mv)
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: Intrinsic brightness of a star
: The apparent visual magnitude the star would have if it were 10 parsec (pc) away. |
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Luminosity (L)
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: the total amount of energy a star radiates in 1 second
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Hertzsprung–Russell (H–R) diagram
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: a plot of intrinsic brightness vs. the surface temperature of stars
–separates the effects of temperature and surface area on stellar luminosity –commonly plotted as Absolute Magnitude vs. Spectral Type –or– Luminosity vs. Surface Temp. of Color |
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Main Sequence
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: the region of the H–R diagram running from upper left to lower right
–includes about 90% of all stars |
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Giant stars
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: Large, cool, highly luminous stars in the upper right of the H–R diagram.
–typically 10–100 times the diameter of the sun |
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Supergiant stars
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: exceptionally luminous star whose diameter is 10–100 times that of the sun
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Red Dwarfs
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: a faint, cool, low–mass, main–sequence star
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White Dwarfs
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: dying stars at the lower left of the H–R diagram that has collapsed to the size of Earth and is cooling off slowly
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Luminosity Class
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: a category of stars of similar luminosity, determined by the widths of lines in their spectra
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Spectroscopic Parallax
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: the method of determining a star's distance by comparing its apparent magnitude with its absolute magnitude as estimated from its spectrum
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Binary Stars
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: pairs of stars that orbit around their common center of mass
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Visual Binary System
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: a binary star system in which the two stars are separately visible in a telescope
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Spectroscopic Binary System
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: a star system in which the stars are too close together to be visible separately
–we see a single point of light –only in a spectrum can the two stars be detected |
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Eclipsing Binary System
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: a binary star system in which the stars eclipse each other
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Light Curve
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: a graph of brightness vs. time commonly used in analyzing variable stars and eclipsing binaries
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Mass–Luminosity Relation
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: the more massive a star, the more luminous it is
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Catastrophe hypotheses
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depend on a rare event such as sun colliding into another star
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Evolutionary hypotheses
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the planets formed by gradual, natural processes
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Solar Nebula Theory
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proposes that the planets formed in a disk of gas and dust around the protostar that became the sun
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Terrestrial planets
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the four inner planets that are small, rocky, and dense
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Jovian planets
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the four outward planets that are large and low density
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Kuiper belt
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composed of small, icy bodies (called Kuiper belt objects) that orbit the sun beyond the orbit of Neptune
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Protoplanets
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unchanged composition of accreted matter over time
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Accretion
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condensated clumps sticking to the other clumps in outer space
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Planetessimals
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bigger clumps of accretion sticking together
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Comparative planetology
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the approach of comparing and contrasting planets to identify principles and understand the planets better
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Why do we use Earth as a standard for comparative planetology
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we know it best and it contains all the phenomena found on the other terrestrial planets
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Which are the terrestrial planets?
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Earth, Moon, Mercury, Venus, Mars
(moon included because it is a complex world and makes a striking comparison to Earth) |
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Terrestrial Worlds
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differ mainly in size
have low–density crusts, mantles made out of dense rock, and metallic cores |
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Main points of Comparative Planetology:
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1. Cratered surfaces are old
2. Heat flowing out of a planet is what drives geological activity 3.The nature of the planet's atmosphere depends on the size of the planet and its temprature |
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4 Stages of Earth's evolution:
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1.differentiation
2.cratering 3.flooding 4.slows surface evolution |
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Differentiation
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the separation of material into layers according to density (earths evolution)
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Cratering
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after a solid surface has formed, heavy bombardment of the early solar system made craters (earths evolution)
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Flooding
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by lava and water (earths evolution)
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Slows surface evolution
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constant changing sections of crust slide over and against each other (earths evolution)
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Seismic waves
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vibrations caused by earthquakes and are detected by seismographs
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Pressure waves
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waves that can pass through a liquid, such as sound
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Shear waves
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travel as a side–to–side vibration and cannot pass through liquid
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Earth
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4.6 billion years old and happened from the inner solar nebula
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Earths core
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liquid (we know that because seismic waves don't travel through it)
composed of iron and nickel |
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Earths mantle
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plastic–like and can deform and flow under pressure
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Earths crust
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brittle and breaks under stress
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Primary atmosphere
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earths first atmosphere that was composed mostly of carbon dioxide, nitrogen, and water vapor
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Secondary atmosphere
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current atmosphere that was composed mostly of carbon dioxide and plants have added oxygen
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Greenhouse effect
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when infrared ration is absorbed by the atmosphere but cannot get back out and heats up the earths surface
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Ejecta
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debris blasted out of craters
(can produce rays and secondary craters) |
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Multiringed basins
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very large pits formed by large impacts
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Micrometeorites
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tiny and constantly bombard the moons surface
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Moon– Highlands
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oldest part of surface and heavily cratered
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Moon– Lowlands
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filled by lava, causing it to be smooth maria
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lunar rocks– Vesicular basalts
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lava–made rocks that contain holes from bubbles
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lunar rocks– anorthosite
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light–colored and low–density rock that floated to the surface of the highlands when it was a magma ocean
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lunar rocks– breccias
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rocks made of fragments of broken rock cemented together under pressure
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Mercury
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–smaller than earth (1/3 of earths diameter)
–larger than the moon –old, heavily cratered surfaces; extremely thin atmosphere –very high density –metallic core is large compared to its diameter |
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Lobate scarps
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long curving cliffs formed by a wrinkling crust, which forms when its large metallic core solidifies and contracts (Mercury)
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Venus
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–almost as large as earth
–can't be seen from earth because of the atmosphere –carbon dioxide in the atmosphere drives an intense greenhouse effect and makes the planet a world of volcanoes and lava flow –slightly closer to the sun than earth |
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Shield volcanoes
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found on Earth, Venus, and Mars, are caused by rising columns of magma (hot spots)
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Composite volcanoes
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only on earth, associated with plate tectonics and subduction zones
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Geological activity
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due to volcanisms and vertical tectonics
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Coronae
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large circular uplifted regions
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Mars
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–half the size of earth
–thin atmosphere; last much internal heat, but not all –cold and has low escape velocity –air pressure is too low for water ––liquid water would boil away ––remaining water is frozen in polar ice caps and as permafrost in the soil |
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water related features– outflow channels
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appear to have been cut by massive floods
(prove that conditions on Mars must have once been different, allowing liquid to flow on the surface) |
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water related features– valley networks
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long term drainage caused riverbeds with sandbars, delta, and tributaries
(prove that conditions on Mars must have once been different, allowing liquid to flow on the surface) |
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Mars Moons
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two moons (Phobos and Deimos)
–most likely captured asteroids –small, airless, cratered –no internal heat left |
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Jovian Planets
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large, massive low–density worlds in the outer solar system
(Jupiter, Saturn, Uranus, Neptune) have extensive satellite systems and moons (regular/irregular) |
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Belt–zone circulation
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cloud belts parallel to the planets equator
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Liquid Giants
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Jupiter and Saturn are composed mostly of liquid metallic hydrogen
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Ice Giants
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Uranus and Neptune are abundant in solid water
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Regular Satellites
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large, close to parent planet, move in prograde direction (with the rest of the solar system)
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Irregular Satellites
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small, far from parent planet, and have high orbital inclinations
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Jupiter
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core made of heavy elements surrounded by a deep mantel of liquid metallic hydrogen
–large and strong magnetic field |
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Magnetosphere
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around Jupiter; traps high–energy particles from the sun to form intense radiation belts
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Atmosphere (Jupiter)
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–three layers of clouds formed of hydrogen–rich molecules
–cloud layers are located at certain temperatures within the atmosphere –cloud stripes parallel to equator are light/dark |
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Jupiter atmosphere cloud stripes
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1. light–colored, high–pressure regions of rising gas
2. darker belts, lower–pressure areas of sinking gas |
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Spots in Jupiter's atmosphere
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includes the Great Red Spot, are circulation weather patterns
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Jupiter's Moons
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–Galilean moons
–linked together in orbital resonances –Io, Europa, Ganymede |
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Io (Jupiters Moon)
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active volcanoes, orbits Jupiter 4 times
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Europa (Jupiters Moon)
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smooth ice and cracks, orbits Jupiter 2 times
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Ganymede (Jupiters Moon)
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grooved terrain, orbits Jupiter once
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Jupiter's ring
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composed of small particles that are bright when illuminated from behind (forward scattering)
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Roche limit
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distance from a planet within which the tidal stress can destroy or prevent one from forming (Jupiter's ring lies within Jupiter's Roche limit)
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Saturn
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–less dense than water
–contains a small core with less metallic hydrogen than Jupiter, therefore magnetic field is 20 times weaker –moons are icy and mostly heavily cratered |
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Titan (Saturn's moon)
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Saturn's largest moon; cold, cloudy nitrogen atmosphere
(so cold that gas molecules do not travel fast enough to escape) |
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Enceladus (Saturn's moon)
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has a light surface with some uncratered regions
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Saturns rings
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composed of icy particles ranging in size from boulders to dust
–composition and brightness of the rings particles vary –grooves in the rings can be produced by orbital resonances, or waves, that propagate through the rings caused by moons near or within the rings |
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Shephard satellites
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the gravitational effect of small moons; can cause narrow rings and sharp ring edges
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Jovian planets rings
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cant be material left over from the formation of the planet
rings are replenished occasionally with material produced by meteoroids, asteroids, and comets colliding with moons |
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Uranus
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–1/3 diameter of Jupiter, 1/20 as massive
–internal pressure cannot produce liquid hydrogen –heavy–element core, mantle of solid or slushy ice and rocky material below a hydrogen–rich atmosphere –atmosphere is almost featureless at visible wavelengths (pale blue color is caused by traces of methane which absorbs red light) –rotates on its side (possibly due to major impact or tidal interactions with other planets during its early history) –larger moons are icy and heavily cratered |
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Ovoids
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grooves on Miranda, the innermost moon, caused by internal heat driving convection in the icy mantle
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Occultations
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the passage of the planet in front of a star during which the rings momentarily blocked the stars light
(how the rings of Uranus were discovered) |
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Rings of Uranus
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narrow hoops of ice with traces of methane confined by shepherd satellites
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Neptune
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–ice giant with no liquid hydrogen
–has heat flowing from its interior –atmosphere is rich in hydrogen and colored blue by traces of methane |
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Nereid (Neptunes Moon)
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far off and follows a large elliptical orbit
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Triton (Neptunes Moon)
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–orbits backwards
–icy with a thin atmosphere and frosty polar caps –smooth areas suggest past geological activity –dark smudges mark the location of active nitrogen geysers |
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Neptunes rings
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made up of icy particles in narrow hoops and contains arcs produced by the gravitational influence of one or more moons
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Pluto
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–small world with 3 moons, one of which, Charon, is quite large in relation to Pluto
–mostly rock with a substantial amount of ice –redefined as a dwarf planet –member of a family of Kuiper belt objects orbiting beyond Neptune |
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Plutinos
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Kuiper belt objects that follow orbits like Pluto that have an orbital resonance with Neptune
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Meteroid
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small solid particles orbiting in the solar system
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Meteor
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visible streak of light from a meteoroid heated and glowing as it enters Earth's atmosphere
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Meterorite
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space material that has reached Earths surface
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Iron meterorites
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solid chunks of iron and nickel
(when sliced open, polished, and etched they show Widmanstatten patterns) |
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Widmanstatten patterns
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reveal that the metal cooled from a molten state slowly
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Stony meteorites
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commonly seen falling to earth
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Chondrites
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dark, gray granular rocks containing chondrules
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Chondrules
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small, glassy particles that are solidified droplets of unknown once–molten material
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Stony–iron meteorites
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rare and a mix of stony and metallic material
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Carbonaceous chondrites
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rich in volatiles and carbon
(some contain CAls (calcium aluminum rich inclusions) which are understood to be the very first solid particles to condense in the cooling solar nebular) |
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CAls
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calcium aluminum rich inclusions) which are understood to be the very first solid particles to condense in the cooling solar nebular)
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Achondrite
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no chondrules or volatiles
(appear to have been melted after they formed) |
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Meteor showers
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suggest that meteorites are fragments of asteroids because they come from the same area in the sky (called the radiant)
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Sporadic meteors
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meteors that occur but are not part of showers
–many meteorites appear to have formed as parts of larger bodies that were broken up –core fragments became iron meteorites –outer layer fragments became stony meteorites –intermediate layers became stony–iron meteorites |
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Asteroids
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–irregular in shape and heavily cratered from collisions
–surface are covered by gray, pulverized rock –some have densities so low they must be fragmented rubble piles –most lie in a belt between Mars and Jupiter |
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Asteroids outside the belt
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–Trojan asteroids
–Near Earth objects –Centaurs |
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Trojan asteroids
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two groups of asteroids caught in the Lagrange point of Jupiter (caught between the gravitational pull of Jupiter and the Sun)
60' ahead of planet in its orbit and 60' behind |
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Near Earth objects
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NEOs that cross the earths orbit and could potentially hit Earth
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Centaurs
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asteroids that orbit among the planets of the outer solar system
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C type asteroids
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common in outer asteroid belt where the solar nebula was cooler; darker and may be carbonaceous
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S type asteroids
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most common and may be the source of chondrites; bright and red
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M type asteroids
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appear to have nickel–iron compositions and may be the cores of different asteroids shatters by collision; bright semi–red |
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Comets
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produced by a lump of ices and rock, referred to as the comet nucleus
–nucleus stars frozen until it nears the sun, then some of the ices vaporize and release dust and gas that is blown away to form a head and tail –comets have very dark, rocky crusts and jets of vapor and dust issue from active regions on the sunlit side –the low density of comet nuclei shows that they are irregular mixtures of ices and silicates –comets are believed to have formed as icy planetessimals in the outer solar system but some were ejected to form the Oort cloud |
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Gas tail
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ionized gas carried away by the solar wind
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Dust tail
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solid debris released from the nucleus and blown outward by the pressure of sunlight |
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Coma
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head of a comet (can be up to a million km in diameter) |
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Oort cloud
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spherical cloud of icy bodies that extend from the sun |