Term
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Definition
medium and large-sized moons probably formed y accretion within the disks of gas surrounding individual jovian planets
have solid surfaces
atmospheres
hot interiors
magnetic fields
strong tidal forces from the parent planet keeps the same side of the moon always facing it |
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Term
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Definition
most volcanically-active world in our solar system
constant variation in tidal forces from Jupiter create the internal friction |
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Term
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Definition
water ice
active geology has erased Europa's old craters
scientists suspect that water did this, rising from underneath the surface
metallic core--rocky mantle--ice |
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Term
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Definition
mix of old and young-looking terrain with sharp boundaries separating the two
suggests occasional upwelling of liquid/slush onto the surface
magnetic field varies with the rotation of Jupiter, suggests the presence of salt water beneath the surface |
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Term
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Definition
ice
dark powder on the surface
lacks volcanic/tectonic features -- no internal heat
ice provides enough insulation for heat from radioactive decay to melt the water beneath the surface |
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Term
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Definition
thick atmosphere filled with chemicals and hydrogen compounds
methane and ethane give it the greenhouse effect
atmospheric chemistry could produce the organic chemicals that are the basis of life
too cold for liquid water
methane/ethane cycle resembling the water cycle on Earth |
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Term
| Saturn's Medium-Sized Moons |
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Definition
most lack geological activity but some show evidence of recent tectonic activity
Mimas is essentially a giant iceball
Enceladus has evidence of ongoing geological activity with an underground liquid reservoir (water geysers) |
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Term
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Definition
largely made of ice (ammonia, methane, and water)
similar sizes but with a large range of geological activity
due to temporary orbital resonance with another moon, which caused tidal heating, Miranda, the smallest moon, shows tremendous tectonic features |
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Term
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Definition
the coldest in the solar system
orbits opposite of Neptune's rotation
captured rather than being formed from Neptune
lots of impact craters AND evidence of geological activity |
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Term
| How is it possible that moons lacking tidal heating have evidence of past activity? |
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Definition
| the icy composition of jovian planets can melt or deform at lower temperatures than rock. This means that most outer solar volcanism produced liquid water/ammonia methane slush instead of lava |
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