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.
Small-scale tectonic stresses
Wrinkles in maria
The present Moon _____ geological active.
Is not
This planetary body is heavily cratered, but not as intensely as the Moon.
Mercury
Why does contracting planet mean?
Most objects contract as they cool.
Mercury was much ________ than the Moon when it formed.
Hotter
Planet that is geologically inactive, or “dead.”
Mercury
There has been some erosion on Mercury from:
Solar winds
What planet has evidence for all four of the major processes?
Mars
On Mars, which Hemisphere is more heavily cratered than the other?
South
Why is it strange that the Southern Hemisphere on Mars is more heavily cratered than the Northern?
The NH is at higher elevations.
What partly explains strong evidence for volcanism in the past on Mars?
Olympus Mons, the largest volcano in our solar system, as well as many other large volcanoes, are on the surface of the planet. Outgassing may also happen on smaller scales than volcanoes.
What is the only substance that could have possibly been on Mars?
Water
What evidence do we have for water on Mars?
- Dried river beds
- Lack of small craters, erased by rain
- River deltas with sedimentary rock
- Large, craterless areas that may have been oceans
- Mineral outcrops that can only be created by water, like gypsum
Why is there a lack of evidence for micrometeoring on Mars?
The micrometeors were erased by rain.
Is there a liquid water on Mars today?
No, but it has frozen water at its poles. Also, liquid water may exist under layers of snow and ice in a few specific areas. This is because snow and ice can provide the pressure to keep water from sublimating (solid to gas).
Venus lacks which of the four surface shaping processes?
Erosion
Venus is covered by clouds. How do we get an image of its surface?
Radar mapping
Venus has very little of which of the four surface shaping processes?
Impact cratering
What is Venus have very little impact cratering?
The smaller meteorites burn up in its atmosphere.
Venus has both shield volcanoes and lava plains. Has there been any recent activity?
There is evidence, but there is none observed.
Venus’s entire surface shows evidence for which of the four surface shaping processes?
Tectonics
Note: it also provides evidence for mantle convection.
This planet has all four surface shaping processes. It has a minimal amount of impact cratering, solid, liquid, and gas, and volcanism. It is most unique for its plate tectonics, because its plates are moving on top of the mantle.
Earth
What evidence was there for the discovery of plate motion and where did this occur?
Rocking fossil; South America and Africa
What are the two types of crust?
Continental: thicker, less dense plate material.
Seafloor: thinner, more dense plate material.
Plates are moved by:
Convection cells
How are seafloor plates recycled in subduction zones?
One plate is pushed under another.
New material is forced _____ expanding plates.
Up
How are continents built?
Because continental crust is less dense, it gets plowed together.
Areas of continents that are separating. They will for new areas for lava flows.
Rifts
Boundaries for plates slide sideways relative to each other.
Faults
Isolated areas where magma reaches the surface
Hot spots
The Earth moves a few ________ a year.
Centimeters
All Jovian planets have a:
Magnetosphere
The Jovian planets’ magnetosphere is ________ due to planet size, it has a stronger magnetic field.
Larger
What are Jupiters two largest moons, which are larger than Mercury?
Ganymede and Titan
Large and medium moons are formed by:
Accretion
What are small moons that are irregular in shape with potentially extremely inclined orbits?
Captured asteroids
What are the four largest moons around Jupiter referred to as?
Galilean Moons
Note: they would all be planets or dwarf planets if they were not orbiting Jupiter.
Jupiter’s Moons:
The most volcanically active world. Its volcanoes are like ones on Earth. Its surface is constantly changing and lacks craters. Sulfur dioxide is the most common gas. Its surface is made up of lava fields and sulfur dioxide frost.
Io
Jupiter’s Moons:
Its surface is made of water ice. There are few impact craters suggesting repaving of surface with liquid water. There’s tidal heating under the surface, creating liquid water. It has a magnetic field induced by Jupiter’s magnetic field. Its conducting fluid is salty ice water. It has three main layers. It is the second farthest moon from Jupiter.
Europa
What are Europa’s three main layers?
- Metallic core
- Rocky interior
- Water surface
(Note: gravity measurements provide evidence for the layers.)
Jupiter’s Moons:
It is the largest moon in the solar system. It has an icy surface. It has dark heavily cratered areas that are older and lightly cratered areas that are young. Has liquid water underneath it surface, but it is deeper. It’s internal thermal energy is from title heating and radioactive decay. It has a magnetic field.
Ganymede
Jupiter’s Moons:
It is a heavily cratered ice ball. It is geologically dead. It has clear regions in its craters. Most of the surface is dark, leftover material from the sublimation of ice. It is the farthest Galilean moon from Jupiter.
Callisto
All of the Jovian planets needed a solid ________ to begin formation.
Planetesimal
Planets ________ to the Sun will have more material for accretion.
Closer
What two Jovian planets are mostly hydrogen and helium?
Jupiter and Saturn
Which two jovian planets are majority hydrogen and helium with hydrogen compounds?
Uranus and Neptune
The density differences between the Jovian planets is due to:
Composition
Jovian planets rotate ________ then terrestrial planets.
Faster
Due to Jovian planets being large, the material in Jovian planets move at a ________ speed.
Greater
The great speed in the Jovian planets causes a ________ in its shape.
Deformation
Do all of the Jovian planets have a rocky core?
Yes. Caused by differentiation. Their deep layers go from solid to liquid to gas.
Jupiter’s internal thermal energy is from:
Contraction
Saturn’s internal thermal energy is from:
Differentiation of liquid helium
Which Jovian planets has no major internal energy source?
Uranus
The Jovian planets have _____ extreme weather due to size and spin rate.
More
________ form at different temperature levels.
Clouds
What are the four layers of atmosphere characterized by temperature change?
- Troposphere
- Stratosphere
- Thermosphere
- Exosphere
Cloud layers determine the ________ we see for each planet.
Color
What are the colors of the Jovian planets and why are they these colors?
Jupiter and Saturn: brown/red and some white; due to ammonia and amenonium hydrosulfate.
Neptune and Uranus: blue; due to methane clouds.
Jupiter’s color bands are caused by the:
Coriolis effect
Global winds are created by the ________ of the planet.
Spinning
Is there a seasonal weather change on Jupiter?
No
How long has the gigantic storm continued on Jupiter?
As long as humans could view it.
Has stronger winds and storms than Jupiter, has bands and seasonal weather change.
Saturn
Lacks strong storms and bands, no internal heating, but has seasonal weather changes.
Uranus
Has storms and bands, less severe storms in Jupiter and Saturn, has a tilt, but does not have seasonal weather changes due to internal heating.
Neptune
What is Saturn’s largest moon?
Titan
Titan has a very ________ atmosphere.
Thick
What types of missions were the Cassini-Huygens missions that explored Titan in 2005? What did they accomplish?
Cassini was an orbiter that received measurements of surface gravity and radar imaging.
Huygens was a lander that took pictures and surface composition.
What was the results of the Cassini-Huygens missions on Titan? What did they find and what does it mean?
Round rocks on surface. Surface shows weathering features. Surface looks like U.S. southwest. Radar images reveal lakes of liquid methane and ethane, meaning Titan has a water cycle like Earth, but with methane and ethane.
What are odd about Saturn’s medium-sized moons Mimas, Enceladus, and Lapetus?
Mimas: Death Star.
Enceladus: no craters.
Lapetus: gray color difference, large ridge on equator.
Saturn’s moon, Enceladus, is geologically ________.
Active
Saturn’s moon, Enceladus, has the possibility of:
Underwater oceans (under ice)
Neptune’s moon, Triton, has an odd orbit. Why? (2)
Highly inclined and backwards to Neptune’s spin.
Triton (Neptune’s moon), because of a possible three-body interaction, is a ________ ________, because of tidal heating present.
Captured moon
Saturn’s rings are made of small particles and _____. They do not grow because of constant collision.
Dust
Waves and ripples in Saturn’s rings are created by ________ ________ by Pan (moon).
Orbital resonance
All Jovian planets have rings.
True
The material for Jovian planet rings come from:
Grinding up of small moons
There are two major groups of asteroids. They are:
- Asteroid Belt: between Jupiter and Mars.
2. Trojan Asteroids: Jupiter’s orbit.
What are asteroids made of?
Rocks and minerals
What is the largest asteroid?
Ceres
Pieces of rocks/ice that fall to the Earth, hit surface.
Hint: Called “meteor” when in the sky.
Meteorites
Dirty balls of ice that come from the Oort belt.
Hint: Tail points away from the sun.
Comets
Has a large moon: Charon, half the size of the planet. Did not clear its own orbit (wasn’t following its own orbital path). Demoted from a planet. Was closer than Neptune at some point. Dwarf planet.
Pluto
What kinds of internal factors shape the terrestrial planets?
Earthquakes and volcanoes
