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50 terms

AST 135 Number Two

STUDY
PLAY
which of the following show evidence of ancient river beds
mars
which of the following planets has the least substantial atmosphere
mercury
what are the spokes in saturn's rings?
particles of dust suspended above the rings by magnetic forces
why do asteroids and comets differ in composition
asteroids formed inside the frost line, while comets formed outside
which planet, other than earth, has visible water ice on it
mars
an icy leftover planetesimal orbiting the sun is
a comet
planetary rings are
all of the above
how do astronomers think saturn generates its interal heat
by raining dense helium droplets from higher to lower altitudes, resembling the process of differentiation
how thick are saturn's rings from top to bottom
a few tens of meters
what is the exosphere
the highest layer in the atmosphere
the most metal-rich terrestrial planet is
mercury
the ionosphere is a layer of ionized gas that is
within the thermosphere
what is the most important factor that determines the thickness, and therefore strength, of the lithosphere
internal temperature
a rocky leftover planetesimal orbiting the sun is
an asteroid
why was the shoemaker levy 9 impact so important to astronomers
it dredged up material that gave us our first direct look at jupiter's interior composition
what is a meteroite
a fragment of an asteroid from the solar system that has fallen to earth's surface
the three principal sources of interal heat of terrestrial planets are
accretion, differentiation, and radioactivity
which of the following worlds has the most substantial atmosphere
venus
which of the following planets has a stratosphere
earth
what are greenhouse gases
gases that absorb infrared light
how do the jovian planet interiors differ
all have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium
the large gaps in the asteroid belt (often called kirkwood gaps) are caused by
orbital resonances with jupiter
which planet has the highest average surface temperature, and why?
venus, because of its dense carbon dioxide atmosphere
most meteorites are
rocky and primitive
the energy in the atmosphere of most of the jovian planets comes___________
both the sun and their interiors, in roughly equal proportions
which of the following best describes the internal layering of jupiter, from the center outward?
core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer
what are the main constituents of the jovian planets
hydrogen and helium
the proper order of the layers of a generic atmosphere from lowest altitude to highest is
troposphere, stratosphere, thermosphere, exosphere
x rays from the sun's corona
are absorbed in earth's thermosphere
olympus mons is a
shield volcano on mars
which is the densest planet in the solar system
earth
why is neptune denser than saturn
it has different composition than saturn, including a higher proportion of hydrogen compounds and rocks
UV light is absorbed in the
stratosphere
why are there no impact craters on the surface of Io?
io did have impact craters but they have all been buried in lava flows
what is the stratosphere
the part of the atmosphere that absorbs ultraviolet
what is the thermosphere
the part of the atmosphere that absorbs x rays
what is the oort cloud
it is not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the sun at great differences
how do astronomers think jupiter generates its internal heat
by contracting, changing gravitational potential energy into thermal energy
what do meteorites reveal about the solar system
they reveal that the age of the solar system is approximately 4.6 billion years
the planet closest in size to earth is
venus
where does nuclear fusion occur in the sun
in its core
which of the jovian planets have rings
all of the above
the main process by which heat flows upward thru the lithosphere is
conduction
what is jupiter's great red spot
a long-lived high pressure storm
the age of the solar system can be established by radioactive dating of
the oldest meteorites
volcanism is more likely on a planet that
has high internal temperatures
which of the following best describes convection
it is the process in which warm material expands and rises while cool material contracts and falls
why is saturn almost as big as Jupiter, despite its smaller mass
jupiter's greater mass compresses it more, thus increasing its density
planet
a moderately large object that orbits a star; it shines by reflected light
asteroid
a relatively small and rocky object that orbits a star