Term
| How do we suppose that the lobate scarps on Mercury's surface formed? |
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Definition
| As Mercury cooled and shrank the crust wrinkled. |
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Term
| Which of the following correctly describes Mercury's spin-orbit resonance? |
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Definition
| Mercury rotates three times about its spin axis for every two orbital revolutions. |
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Term
| How did the Moon achieve its synchronous rotation? |
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Definition
| The Earth raises tidal bulges on the Moon. As the Moon rotated through these bulges internal friction slowed the Moon's rotation until it achieved tidal coupling. |
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Term
| How do we find the relative ages of the Moon's maria and highlands? |
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Definition
| By counting the number of impact craters. |
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Term
| Coincidental agreement between two periodic phenomena; commonly applied to agreements between orbital periods |
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Definition
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Term
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Definition
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Term
| Apparently young plains on Mercury formedby lava flows at or soon after the formation of Caloris Basin |
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Definition
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Term
| Relatively smooth terrain on Mercury; less heavily cratered than oldest terrain. |
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Definition
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Term
| Lunar lowlands filled by successive flows of dark lava. |
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Definition
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Term
| Narrow, winding valley caused by ancient lava flows along narrow channels |
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Definition
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Term
| Pulverized rock scattered by meteorite impacts on a planetary surface. |
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Definition
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Term
| Ejecta from a meteorite impact forming light colored streamers radiating from some impact craters. |
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Definition
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Term
| Age of a geologic feature referred to other features; e.g., lunar maria are younger than highlands. |
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Definition
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Term
| Age determined in years, as from radioactive dating. |
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Definition
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Term
| Rock composed of fragments of earlier rocks bonded together. |
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Definition
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Term
| Soil made up of crushed rock fragments |
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Definition
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Term
| Very large impact basins in which there are concentric rings of mountains |
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Definition
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Term
| Topography low associated with a gravity high; often found in near-side lunar impact basins; short for "mass concentrations" |
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Definition
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Term
| How is the planet Mercury different than Earth's Moon? |
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Definition
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Term
| What evidence do we have that Mercury has a partially molten, metallic core? |
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Definition
| Mercury has a weak dipole magnetic field |
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Term
| Wide, low-profile volcanic cone produced by highly liquid lava |
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Definition
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Term
| Round networks of fractures and ridges |
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Definition
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Term
| Process by which a carbon dioxide atmosphere traps heat and raises the temperature of a planetary surface |
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Definition
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Term
| Volcano built up by layers of lava flows and ash falls; steep sided and generally associated with subduction zones |
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Definition
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Term
| A measure of the velocity of random motions among atoms or molecules in a material |
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Definition
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Term
| Geological features that appear to have been formed by sudden flooding |
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Definition
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Term
| All of the dormant volcanoes on Venus and Mars are the shield type, and many are much larger than any shield volcano on Earth. What does this tell us about Venus and Mars? |
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Definition
| Neither Venus nor Mars has plate tectonics |
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Term
| Measurements from orbiting spacecraft suggests that Mars had a magnetic field in its past. How could Mars lose its magnetic field? |
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Definition
| Mars has cooled to the point that it no longer has a fluid interior. |
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Term
| Why are Phobos and Deimos not spherical? |
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Definition
| Their gravity fields are too weak to pull their material into a spherical shape. |
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Term
| Which gas is most abundant in the atmospheres of Venus and Mars? |
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Definition
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Term
| Why is the surface temperature of Venus higher than that of any other planet? |
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Definition
| It has an extreme greenhouse effect. |
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Term
| What determines whether an atmospheric gas can be retained by a planet rather than be lost to space? |
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Definition
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Term
| What evidence do we have that Mars had much more liquid water at its surface in the past than it has today? |
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Definition
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Term
| Why might Venus have the slow retrograde rotation that is observed? |
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Definition
| Both A large off center impact may have set Venus to spinning backwards and The long-term effect of solar tides on its dense atmosphere may be responsible. |
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Term
| How do we know what the surface of Venus looks like? |
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Definition
| Radar mapping at radio wavelengths allows us to determine surface elevations. |
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Term
| Jupiter's mass is approximately 0.001 solar masses. How is the mass of Jupiter determined? |
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Definition
| Both We use Newton's form of Kepler's third law and We can use the period and semimajor axis of Callisto's orbit around Jupiter. |
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Term
| What evidence do we have that Jupiter has a very hot interior? |
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Definition
| It emits 70% more energy at infrared wavelengths than it receives from the sun. |
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Term
| Which method of heat transfer is responsible for Jupiter's belts & zones, and the Great Red Spot? |
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Definition
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Term
| The two requirements for a strong planetary magnetic field are rapid rotation and a convective interior zone composed of an electrically conductive material. Jupiter's rotational period is slightly less than 10 hours. What type of matter fulfills the second requirement? |
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Definition
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Term
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Definition
| The maximum distance from a planet at which planetary rings can exist. |
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Term
| What evidence do we have that Io's crust and lava is mostly silicate rock rather than sulfur compounds? |
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Definition
| Both Some mountains on Io are much higher than any mountains on Earth and Much of the lava flowing from Io's volcanoes is hotter than Earth lava. |
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Term
| What evidence supports the model of Jupiter's Galilean satellites forming in a mini accretion disk around Jupiter? |
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Definition
| Both The density trend of these four moons is highest close to Jupiter and decreases with distance and The two inner moons are much smaller than the two outer moons of this group. |
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Term
| Band of dark clouds that circle Jupiter/ Saturn parallel to equator; believed to be regions of descending gas. |
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Definition
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Term
| Atmospheric circulation typical of Jovian planets with dark belts and bright zones parallel to planet's equator. |
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Definition
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Term
| Flattening of a spherical body; usually caused by rotation |
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Definition
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Term
| A form of hydrogen under high pressure that of a good conductor of electricity. |
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Definition
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Term
| A doughnut shaped cloud of ionized gas that encloses the orbit of Jupiter's moon Io |
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Definition
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Term
| A band of clouds that circle Jupiter/Saturn parallel to the equator; believed to be areas of rising gas. |
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Definition
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Term
| Minimum distance between a planet and a satellite that holds itself together by its own gravity. If satellite moves within the planet's Roche limit, tidal forces will pull the satellite apart. |
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Definition
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Term
| Heating of a planet of satellite because of friction caused by tides |
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Definition
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Term
| Satellite that, by its gravitational field, confines particles to a planetary ring. |
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Definition
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Term
| What evidence do we have that Jupiter is primarily composed of hydrogen and helium rather than rock? |
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Definition
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Term
| What energy source drives the weather that we see on Jupiter? |
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Definition
| Thermal energy escaping from Jupiter's interior that is still hot from formation. |
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Term
| In the 1950s radio telescopes first detected synchrotron radiation from Jupiter. What did this discovery tell us about Jupiter? |
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Definition
| Jupiter has a strong magnetic field. |
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Term
| Jupiter's ring appears dark in back scattered light, yet appears bright in forward scattered light. What does this tell us about the particles that make up Jupiter's ring? |
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Definition
| Both The particles' average diameter is a few micrometers and The particles are most likely dust. |
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Term
| How does Ganymede differ from Callisto? |
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Definition
| Ganymede is differentiated and Callisto is not. |
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Term
| The density of Callisto is 1.8 grams per cubic centimeter and that of Ganymede is 1.9 grams per cubic centimeter. What does this suggest about these outer two of Jupiter's four big moons? |
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Definition
| These two moons must be made of roughly equal volumes of ice and rock. |
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Term
| What evidence do we have that the surface of Europa is young and active? |
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Definition
| Both Europa has very few impact craters and The icy crust of Europa is highly reflective. |
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Term
| Why are Europa, Ganymede, and Callisto necessary for the continued heating of Io? |
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Definition
| These moons periodically tug on Io and keep its orbit elliptical. |
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Term
| In which way does Saturn differ from Jupiter? |
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Definition
| Saturn has a smaller zone of liquid metallic hydrogen. |
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Term
| How do Saturn's three layers of clouds differ from Jupiter's three layers of clouds? |
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Definition
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Term
| What gives Saturn's rings their beautiful structure? |
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Definition
| The gravitational influence of Saturn's moons on the ring particles. |
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Term
| How can Titan have a nitrogen-methane atmosphere with a surface pressure 1.5 times that of Earth's atmosphere, whereas the larger and more massive Ganymede has no atmosphere at all? |
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Definition
| Titan is farther from the sun and thus colder Ganymede |
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Term
| What causes the leading side of Saturn's small moon Iapetus to differ from its trailing side? |
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Definition
| The leading side is darker as it collides with and captures dark dust |
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