Exam 3 Flashcards
What kind of external factors shape the terrestrial planets?
Bombardment
Some processes that shape the terrestrial planets may be ________. Examples of this may be plate tectonics an asteroid impacts.
Slow
Interior factors affect what we see on the:
Surface
We can examine the interior of the Earth and Moon by ________ ________ from earthquakes.
Seismic waves
The overall density of other planets is the combination of:
Surface and overall density
Determined by the interior layers that generate it.
Magnetic fields
Gives the interior composition of rock.
Emerged surface rock
Denser material is pulled towards the center of the planet
Differentiation
What are the three layers starting from the surface to the most inner part?
Crust, mantle, core
The top rigid layer
Lithosphere
Why are planets round?
Gravitational force
What are the three methods of interior thermal energy?
- Accretion (potential energy to kinetic, to thermal)
- Differentiation (potential energy to thermal via friction)
- Radioactive decay (mass-energy to thermal energy)
When do the two interior heating processes of the planet, accretion and differentiation, work?
When the planet is young
What are the three methods of interior cooling?
- Convection (cooling by hotter material moving to an area of cooler material)
- Conduction (cooling through close contact to a cooler object)
- Radiation (cooling by emitting energy in forms of a wave)
How does size affect geological activity?
Smaller planets cool faster.
What are the two terrestrial bodies that do not have heat driven geological activity?
Mercury and the Moon
What planets still have heat driven activity?
Venus, Earth, and Mars
What are the three parameters needed to create a magnetic field?
- And interior region of electrically charged conductive fluid.
- Convection in fluid layer.
- Moderately rapid spin.
What planets have a magnetic field due to the three parameter process?
Earth and Jovian planets
Which planet’s magnetic field is a mystery?
Mercury
What are the four major processes of planetary surface shaping?
- Volcanism
- Tectonics
- Erosion
- Impact Cratering
Which of the planetary surface shaping processes are internal? External?
Internal: Volcanism, Tectonics, and Erosion
External: Impact Cratering
Caused when an asteroid or comet impacts the surface of a planet.
Impact cratering
What two planetary bodies have been heavily impacted by impact cratering?
The Moon and Mercury
What planetary body has been moderately impacted by impact cratering?
Venus
What planetary body has been rarely impacted by impact cratering?
Earth
When did most of the impact cratering occur?
The Heavy Bombardment Period
How can craters provide clues about the geological past?
- Crater size is proportional to the object’s size.
- Leftover debris gives the age of the crater.
- Features tell us what was present at the time of impact.
Occurs when molten rock (magma) reaches the surface of a planet.
Volcanism
What are the three reasons why volcanism occurs?
- Molten rock is less dense than solid rock.
- Pressure or solid rock squeezes molten rock.
- Trapped gases push magma up.
Molten rock inside/underground
Magma
Molten rock above ground
Lava
What type of volcano has the thinnest magma, and creates smooth level plains?
Volcanic Plains
What type of volcano has medium thickness, and is talk but not steep?
Shield Volcanoes
What type of volcano has the thickest magma, cools very quickly, and has steep slopes?
Stratovolcanoes
When gases escape the interior of the Earth?
(Hint: Can happen slowly from vents, or rapidly from volcanic eruptions, and created most of the atmosphere of the terrestrial planets.)
Volcanic outgassing
Refers to the shaping of the surface features by forces acting in the lithosphere.
Tectonics
Most of tectonics activity is a result of:
Mantle convection
In tectonics, mantle activity breaks the crest into plates. This causes:
Movement of plates (plate tectonics)
What types of erosion are there?
Solid, liquid, and gas erosions
Erosion: what type of matter is a glacier erosion?
Note: Glacier erosions are glacier movement across landscape.
Solid
Erosion: what type of matter is a water erosion?
Note: Water erosion is water moving across a landscape.
Liquid
Erosion: what type of matter is wind erosion?
Note: Wind erosion is air moving across a landscape.
Gas
Are heavily cratered areas young or old?
Old
How can we tell the geological age of a cratered surface?
The number of craters, debris, and rock leftover
Volcanism and plate tectonics depends on ________ ________ ________.
Internal thermal energy
Smaller planets have lost most of their ________ energy.
Thermal
Erosion depends on the ________ in the atmosphere.
Weather
Smaller planets lack a significant ________.
Atmosphere
Only Venus and Earth have ________.
Weather
What is the issue with fluid and Impact cratering?
Fluid surfaces leave no evidence of cratering.
Larger planets take _____ time to lose their thermal energy.
More
Planets closer to the sun had _____ thermal energy at their time of formation, and receive _____ energy from the sun.
More; more
A faster ________ planet has more weather and a stronger magnetic field.
Spinning
What two planetary bodies look very similar today and must have a closely related geologic history?
Mercury and the Moon
On the moon, there is evidence for: (2)
Volcanism and tectonics
Dark, smooth areas on the Moon
Maria
Why are the marias dark and smooth?
They are the result of surface lava after the bombardment period.