Phys 1080: Exam 2 (Ch.15-19)

Front 1

Comparative Planetology

Back 1

: the approach of comparing and contrasting planets to identify principles and understand planets better

*We use Earth as a standard for comparative planetology b/c we know its best and it contains all the phenomena found on the other Terrestrial planets

Front 2

The Terrestrial Worlds

Back 2

-Differ in Size

ALL HAVE:

1) Low-density crusts

2) Mantles made of dense rock

3) Metallic cores

Front 3

Terrestrial Planets

Back 3

include: Earth, the Moon, Venus, & Mars

*moon is included b/c it is a complex world and makes a striking comparison to Earth

Front 4

Comparative Planetology: Key Points

Back 4

1) Cratered surfaces are old

2) Heat flowing out of a planet is what drives geological activity

3) The nature of the planet's atmosphere depends on the size of the planet and it's temperature

Front 5

4 Stages of Earth's Evolution

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1) Differentiation: the separation of material into layers according to density

2) Cratering: after a solid surface has formed, heavy bombardment of the early solar system made craters

3) Flooding: by lava and water

4) Slows Surface Evolution: constant changing sections of crust slide over and against each other

Front 6

Seismic Waves

Back 6

: Vibrations caused by earthquakes and are detected by seismographs

Front 7

Pressure Waves

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: waves that can pass through a liquid, such as sound

Front 8

Shear Waves

Back 8

: travel as a side-to-side vibration and cannot pass through liquid

Front 9

Earth's Structure

Back 9

-4.6 billion years old and happened from the inner solar nebula

-Core: liquid (we know that b/c seismic waves don't travel through it) and composed of iron and nickel

-Mantle:plastic-like and can deform and flow under pressure

-Crust: brittle and breaks under stress

Front 10

Primary Atmosphere

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: Earth's first atmosphere that was composed mostly of carbon dioxide, nitrogen, and water vapor

Front 11

Secondary Atmosphere

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: current atmosphere, seawater absorbed most of the carbon dioxide and plants have added oxygen

Front 12

Greenhouse Effect

Back 12

: process by which carbon dioxide in the atmosphere traps heat and raises the temperature of the planets surface

Front 13

Ejecta

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: debris blasted out of craters

*can produce rays and secondary craters

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Multiringed Basins

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: very large pits formed by large impacts

Front 15

Micrometeorites

Back 15

: tiny and constantly bombard the Moon's surface

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the Moon's Surface

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Highlands: oldest part of surface and heavily cratered

Lowlands: filled by lava, causing it to be smooth maria

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Lunar Rocks: Vesicular Basalts

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: lava-made rocks that contain holes and bubbles

Front 18

Lunar Rocks: Anorthosite

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: light-colored and low-density rock that floated to the surface of the highlands when it was a magma ocean

Front 19

Lunar Rocks: Breccias

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: rocks made of fragments of broken rock cemented together under pressure

Front 20

Mercury

Back 20

-smaller than Earth (1/3 of Earth's diameter)

-larger than the Moon

-old, heavily cratered surfaces

-extremely thin atmosphere

-very high density (metallic core is large compared to its diameter)

-Lobate scarps

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Lobate scarps

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: long curving cliffs formed by a wrinkling crust, which forms when it's large metallic core solidifies and contracts

Front 22

Venus

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-almost as large as Earth

-can't be seen from Earth b/c of the atmosphere

-CO2 in atmosphere drives and intense greenhouse effect and makes the planet a world of Volcanoes and lava flow

-Slightly closer to the sun than Earth

-Shield Volcanoes

-Geological activity due to volcanism and vertical tectonics

-Coronae: large circular uplifted regions

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Shield Volcanoes

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-found on Earth, Venus, and Mars

-Caused by rising columns of magma (hot spots)

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Composite Volcanoes

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-only found on Earth

-associated with plate tectonics and subduction zones

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Mars

Back 25

-1/2 size of Earth

-thin atmosphere

-cold and has low escape velocity

-air pressure is too low for water

>liquid water would boil away

>remaining water is frozen in polar caps and as permafrost in the soil

-water-related features:

>outflow channels: appear to have been cut by massive floods

>valley networks: long-term drainage caused riverbeds with sandbars, delta, and tributaries

-has 2 moons (Phobos & Deimos)

Front 26

Jovian Planets

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-large, massive low-density worlds in the outer solar system

-Includes: Jupiter, Saturn, Uranus, Neptune

Front 27

Belt-zone Circulation

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: cloud belts parallel to the planet's equator

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"Liquid Giants"

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Jupiter and Saturn are composed mostly of liquid metallic hydrogen

Front 29

"Ice Giants"

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Uranus and Neptune are abundant in solid water

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Jovian Satellite Systems

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*all Jovian worlds have extensive satellite systems classified as:

Regular Satellites-large, close to parent planet, move in prograde direction (with rest of the solar system)

Irregular Satellites-small, far from parent planet, have high orbital inclinations

Front 31

Jupiter

Back 31

-core made of heavy elements surrounded by a deep mantle of liquid metallic hydrogen (large and strong magnetic field)

-Magnetosphere: around Jupiter; traps high-energy particle from the sun to form intense radiation belts

-Atmosphere:3 layers of cloudes formed of hydrogen-rich molecules

-Moons: Galilean moons

-Ring

-Roche Limit

Front 32

Jupiter's Magnetosphere

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-around Jupiter

-traps high-energy particle from the sun to form intense radiation belts

Front 33

Jupiter's Atmosphere

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-3 layers of cloudes formed of hydrogen-rich molecules

-cloud layers are located at certain temperatures w/in the atmosphere

-cloud strips parallel to equator are:

---1-light-colored, high-pressure regions of rising gas

---2-darker belts, lower-pressure areas of shrinking gas

-spots in Jupiter's atmosphere, including the Great Red Spot, are circulating weather patterns

Front 34

Jupiter's Moons

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Galilean moons

-linked together in orbital resonance

-Lo: active volcanoes, orbits Jupiter 4 times

-Europa: smooth ice and cracks, orbits 2 times

-Ganymede: grooved terrain, orbits once

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Jupiter's Ring

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: composed of small particles that are bright when illuminated from behind (forward scattering)

-Lies within the Roche Limit

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Jupiter's Roche Limit

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: the distance from a planet within the tidal stress can destroy or prevent one from forming

*Jupiter's ring lies within the Roche Limit

Front 37

Saturn

Back 37

-less dense than water

-contains a small core w/ less metallic hydrogen than Jupiter, therefore its magnetic field is 20 times weaker

-Saturn's moons are icy and heavily cratered

-Rings: composed of icy particles ranging in size from boulders to dust

-Shephard satellites

Front 38

Saturn's Moons

Back 38

Titan:

-Saturn's largest moon

-cold, cloudy nitrogen atmosphere

-so cold that gas molecules do not travel fast enough to escape

Enceladus:

-has a light surface with some uncratered regions

Front 39

Saturn's Rings

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: composed of icy particles ranging in size from boulders to dust

-composition and brightness of the rings' particles vary

*grooves in the rings can be produced by orbital resonances, or waves, that propagate through the rings, caused by the moons near or within the rings

Front 40

Saturn's Shephard Satellites

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: the gravitational effect of small moons; can cause narrow rings and sharp edges

-Jovian planets' rings cant be material left over from the formation of the planet; rings are replenished occasionally with material produced by meteoroids, asteroids, and comets colliding with moons

Front 41

Uranus

Back 41

-1/3 the diameter of Jupiter, 1/20 as massive

-internal pressure cant produce liquid hydrogen

-heavy-element core, mantle of solid slushy ice and rocky material below a hydrogen-rich atmosphere

-atmosphere is almost featureless at visible wavelengths (*pale blue color is caused by traces of methane, which absorbs red light)

-rotates on it's side

-Uranus' larger moons are icy and heavily cratered

-Oviods

-Occultations

-Rings

Front 42

Uranus: Ovoids

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: grooves on Miranda (the innermost moon) cause by internal heat driving convection in the icy mantle

Front 43

Uranus: Occultations

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: the passage of the planet in front of a star during which the rings momentarily blocked the star's light

***How the rings of Uranus were discovered

Front 44

Uranus: Rings

Back 44

-narrow hoops of ice with traces of methane confined by shepherd satellites