Geo 109 Final
What causes the Cassini Division, the 400 km wide break in the rings of Saturn?
orbital resonance of the ring particles with the satellites
In what ways are the icy moons of Uranus different from those of Saturn?
slightly higher densities
The nucleus of a comet... (appearance)
small and dark
Why aren't running water and erosion important geologic agents on all planets?
some planets lack solid surfaces, some are too cold, some have the wrong composition for water to exist, some are too hot
The tail of a comet develops...
temporarily when the comet enters the inner solar system
What planetary body has the oldest surface?
the Moon
What are the major differences between Io and Europa?
the composition and surface materials (NOT SIZE, DENISTY, OR AGE)
Differences in the appearance of multiring basins on the Moon with those developed on Callisto are thought to be the result of what?
the difference in the behavior of ice and silicates wen impacted
What is the most important in keeping liquid water on Earth
the distance from the Sun
The Roche limit is...
the distance inside which orbiting materials will not accrete together, produced by tidal interaction between two planetary bodies
The Oort Cloud contains...
the orbit of comets in the outer part of the solar system
Why isn't Earth heated by tidal flexing?
the orbit of the moon is nearly circular, Earth only has one large moon unlike Jupiter
Why are the histories of the small icy satellites of Saturn and Uranus dominated by expansion, unlike the inner planets dominated by contraction?
the outer planets satellites have a lot of water ice that expands as it freezes
Why are the planetary bodies of the inner solar system different in composition from those of the outer solar system?
the planets formed in a thermal gradient around the ancient sun, high-temp solids could form near the ancient sun, large icy cores attracted hydrogen and helium from the nebula
What is the most important control on a planet's present level of geologic activity (especially volcanic and tectonism)?
the thickness of its lithosphere
As a dense particle in a planet moves toward the core, the loss of gravitational potential energy is converted to what energy?
thermal
The icy layers of Jupiter's satellites increase in thickness as one moves from Europa to Callisto because...
they accreted in a thermal gradient centered around Jupiter
Comets glow in the night sky because
they reflect the light from the Sun
the absence of large folded mountain systems on the Moon, Mars, and Mercury is evidence that the lithospheres of these planets...
thickened rapidly as these worlds cooled
The tall mountains of Pluto are composed of what kind of ice?
water
important components of a comet
water ice, silicate materials like olivier, methane, ammonia, carbon dioxide and carbon monoxide
The grooved terrain of Ganymede is (relative age)
younger than its cratered terrain
What is the evidence that Ganymede and Callisto have more ice in their interiors than Io and Europa do?
Ganymede and Callisto have lower densities
What body is Pluto most similar to in size, composition, and density?
Triton
The dark reddish regions on Charon's north pole result from what process?
Methane and organic molecular deposits from Pluto that condense at Charon's poles
Would you expect to find young basaltic lava flow at the surface of Callisto?
No because it's too cold and does not have silicates near the surface that could melt
How did Pluto's Sputnik Planitia form?
a large impact basin filled with weak nitrogen ice
What is a common process that occurred during the evolution of the satellites of Uranus?
cracking as they expanded late in their histories
Appearance of surface of Europa
crisscrossing stripes and fractures
What do the arrows in the image of Pluto show?
glacial flow directions
What is the most important source of energy that drives the circulation of Saturn's atmosphere?
great rising from the interior
What is the most of abundant of the games comprising Saturn?
hydrogen
Where is Saturn's Roche limit for small icy bodies in orbit around it?
near the outer edge of the rings
Pluto's atmosphere is tenuous and temporary, but what are its constituents?
nitrogen and methane that sublime from the most volatile ices on its surface
which of the Galilean satellites has the most heavily created surface?
Callisto
How did the multiple rings of Valhalla on Callisto form?
Crustal breakage as impact shock waves traveled through the surface
What gives Saturn a yellowish tint?
Crystals of ammonia ice and hydrocarbons in the atmosphere
If you were a solar system explorer in search of liquid water at or near the surface, which of the satellites of Jupiter would be most likely to have it today?
Europa
The composition of the surface of Ganymede is most like which of the other satellites of Jupiter?
Europa
The age of the surface of Europa is like which of the satellites of Jupiter?
Io
What's the most volcanically active body in the solar system?
Io
Statements about the Kuiper belt
It contains many small icy objects in orbit around the Sun; the orbits formed a flattened disk in the outer solar system; Pluto is one of the bodies in the Kuiper belt
Suppose a new planet has been discovered between Venus and Earth and is about the size of Earth's moon. What is probably true?
It should be intensely cratered and lack a thick atmosphere
Why is Uranus considered so odd compared to other planets?
Its spin axis is tipped from vertical by over 90 degrees
Saturn is the most similar in composition and internal structure to what planet?
Jupiter
How do Jupiter and Saturn compare?
Jupiter is denser and has more large satellites
In what ways is the Oort Cloud different than the Kuiper belt?
Oort Cloud is spherical, not disk-shaped; most long period comets come from the Oort Cloud
On Ganymede, grooved terrain formed by which process?
Tectonic disruption of heavily cratered terrain
What is the most likely explanation for Saturn's magnetic field?
The magnetic field forms by convection in a shell of metallic hydrogen
What is the origin of the light-colored streaks extending from the surface of comet Churyumov-Gerasimenko?
The streaks are plumes of dust and gas ejected from the interior as the Sun heats it
Why is Uranus so much smaller than Saturn and Jupiter?
There was not enough nebular gas and dust near the region where Uranus formed
In what way is Io similar to Earth's Moon?
about the same size, about the same density, both tidally locked with one face pointed towards their host planet
How did the palimpsests on Ganymede form?
as the icy lithosphere flowed to fill in an impact crater
Why is Pluto considered a dwarf planet by many astronomers?
because it has not cleared its orbital path of debris
Why are comets thought to have originated in a different part of the solar nebula than asteroids?
because they are composed mostly of ices
How did the polygonal shapes on Pluto's Sputnik Planitia form?
by convection within the glacial ice
The particles in the rings of Uranus are...
dark and probably composed of darkened methane ice
General history of catering on a planet
early heavy catering with declining intensity, then intense bombardment, then declining intensity to present
In what way is the magnetic field of Uranus distinctive?
it has an unexpected orientation, it's tilted compared to the spin axis, it is irregular and may be experiencing a reversal
The surface of Io is thought to be less than a million years old because
it has not impact craters
In what way is Earth's atmosphere unique among the moons and planets?
it is rich in oxygen
What is true of the properties of Churyumov-Gerasimenko?
it is very dark because of the presence of organics, it is extremely low in density suggesting pore space inside
What are Saturn's rings composed of?
many small particles of water ice in orbit around Saturn