Quark’s Holiday Tour Part II: the Inner Planets of Sol N. Lindsley-Griffin, 1998 Mars Venus Terra Mercury Jupiter

Quark’s Holiday Tour Part II: the Inner Planets of SolQuark’s Holiday Tour Part II: the Inner Planets of Sol

N. Lindsley-Griffin, 1998

Mars Venus

TerraMercury

Jupiter

Composition - All have:

metallic core

siliceous mantle

basaltic crust

Relatively dense: 4 - 5.5 g/cm3

Different history from Jovians

All shaped by:

1. Impact cratering

2. Volcanism

3. Tectonism

4. Erosion and deposition

Houghton-Mifflin, Dolgoff, 1998; N. Lindsley-Griffin, 1999

Geology of Terrestrial Planets

Quark’s Holiday Tour

Geology of Terrestrial Planets


Terra (“Earth”)

Venus

Mars

Luna

(“Moon”)

Mercury

A planet’s evolution is controlled by how long internal heat lasts

Luna (Earth’s Moon) is small, became quiet 3 b.y. ago

Terra (“Earth”) is large, stilll hot, remains dynamic today


Evolution of Terrestrial Planets Quark’s Holiday Tour Evolution of Terrestrial Planets Quark’s Holiday Tour

Venus - carbon dioxide

Earth - nitrogen/oxygen

Mars - carbon dioxide

Venus - runaway greenhouse effect

No plate tectonics

Too much Solar energy

Earth - plate tectonics recycles oxygen

by subducting and remelting

oceanic lithosphere and sediments

Carbon dioxide trapped biogenically

Size and mass just right to maintain

internal heat that drives tectonic cycle

Mars - water, oxygen locked up in rocks

No plate tectonics

Too small to hold dense atmosphere


Atmospheres - Venus, Earth, Mars Quark’s Holiday Tour Atmospheres - Venus, Earth, Mars Quark’s Holiday Tour

Crater Density and Age of SurfaceMany craters on older, original lunar crust (anorthosite brecciated by repeated impacts)

Fewer craters on younger crust of basalt in the lunar mare (dark colored basins)

Crater density provides relative dating for lunar surfaces


LUNA Quark’s Holiday Tour LUNA Quark’s Holiday Tour

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MARS: Tectonics Quark’s Holiday Tour MARS: Tectonics Quark’s Holiday Tour

Huge rift valleys (grabens) cut the northern hemisphere

Valles Marineris, largest canyon in the solar system, is 4500 km long, 2-7 km deep, formed by crustal rifting


Tharsis Bulge, shield volcanoes

Valles Marineris, a graben

MARS: Olympus Mons Quark’s Holiday Tour MARS: Olympus Mons Quark’s Holiday Tour

Largest volcano in the solar system

Shield Volcano

Summit Caldera

Larger than the entire Hawaiian islands

No linear track (therefore no plate tectonics)


MARS: Atmosphere Quark’s Holiday Tour

MARS: Atmosphere Quark’s Holiday Tour

Atmosphere is thin,

rich in CO2

Iron in rocks has weathered to red oxides

Winds produce ventifacts and dune fields, deposit wind-blown sediments N. Lindsley-Griffin, 1998

MARS: Climate and Ice CapsQuark’s Holiday Tour MARS: Climate and Ice CapsQuark’s Holiday Tour

Strongly elliptical orbit causes huge variation in seasons

Average temp. -55°C (-67°F), but ranges from winter low of

-133°C (-207°F) to summer high of 27°C (80°F)

Ice caps wax and wane with the seasons, causing 25% change in global atmospheric pressure


Ice caps at both poles are carbon dioxide (“dry ice”) with dust and minor water ice.

MARS: Water Cycle Quark’s Holiday Tour MARS: Water Cycle Quark’s Holiday Tour

Liquid water cannot exist on surface today

No water cycle active today

Evidence of

water erosion

and deposition

in the past

Major climate change


MARS: Water Cycle Quark’s Holiday Tour MARS: Water Cycle Quark’s Holiday Tour

Large floods

Small river systems

Large lakes or even oceans


Nirgal Vallis, a runoff channel

Fault-bounded canyon

Runoff caused by impact?

VENUS: Atmosphere Quark’s Holiday Tour VENUS: Atmosphere Quark’s Holiday Tour

Pressure: 90 atm.

Dense clouds of CO2 and sulfuric acid conceal surface

Runaway greenhouse effect

traps solar heat at surface

Surface temperature 500o C

(melts lead)


VENUS: Radar View of Surface Quark’s Holiday Tour VENUS: Radar View of Surface Quark’s Holiday Tour

No rivers, oceans

Surface 500°C - greenschist

metamorphism

No plate tectonics - only hot spot

volcanismN. Lindsley-Griffin, 1998

VENUS: Mountains and Faults Quark’s Holiday Tour VENUS: Mountains and Faults Quark’s Holiday Tour

Linear features are tension cracks (normal faults)

Structures are horsts and grabens like the Basin and Range Province

Form over rising or sinking mantle

plumes


Normal Faults Grabens

VENUS: Volcanoes, Lava Flows Quark’s Holiday Tour VENUS: Volcanoes, Lava Flows Quark’s Holiday Tour

Radar images show large shield volcanoes

Entirely basaltic crust

- no granite

Fresh, uncratered

lava flows


Sif Mons, a shield volcano

Bright radar images are rough aa lava

Dark lava flows are smooth, less reflective, pahoehoe lava

Maat Mons Volcano, Venus

The entire surface of Venus is covered by 500 m.y. basalt

Suggests a catastrophic resurfacing event

Sparse impact crater density -little modification since then

Older Lava Flow

Older Lava Flow

Younger Lava Flow

Younger Impact Crater


MERCURY Quark’s Holiday Tour MERCURY Quark’s Holiday Tour

Closest planet to Sol

Smaller than all other planets except Pluto

No atmosphere

Rotates only 3 times in 2 of its years


MERCURY: Geology Quark’s Holiday Tour MERCURY: Geology Quark’s Holiday Tour

Surface very old, heavily cratered, similar to Luna

Huge lava plains like Lunar maria


Sol: Close Approach Quark’s Holiday Tour Sol: Close Approach Quark’s Holiday Tour

As we zoom around Sol on our way to Terra….


Dark sunspots are relatively “cool” regions

Solar flare or prominence

TERRA - LUNA


TERRA - LUNA


The moon Luna is 1/4 the diameter of Terra

Some scientists consider these to be paired planets

like Pluto - Charon

Luna’s relatively great mass affects ocean tides

on Terra


LUNAR GEOLOGY Quark’s Holiday Tour LUNAR GEOLOGY Quark’s Holiday Tour


Terrae, or lunar highlands (red color), the older crust under basalt lava flows

Maria, or lunar lava

flows, (blue and orange color) are the younger lowlands

Tycho crater:

Rays of young ejecta cut across older features

LUNAR METEORITE IMPACT Quark’s Holiday Tour LUNAR METEORITE IMPACT Quark’s Holiday Tour

Large crater excavated by impact.

Meteorite disintegrates, debris scatters all around.

Secondary craters formed by impact of larger ejecta fragments.


ORIGIN OF LUNAR MARIA

Impact forms normal faults and ring fractures around crater

Basaltic magma forms by pressure-release melting, ascends through fractures

to fill crater.

Result: younger, less cratered basaltic maria.


LUNAR METEORITE IMPACT Quark’s Holiday Tour LUNAR METEORITE IMPACT Quark’s Holiday Tour

Crater Density and Age of SurfaceMany craters on older, original lunar crust (anorthosite brecciated by repeated impacts)

Fewer craters on younger crust of basalt in the lunar mare (dark colored basins)

Crater density provides relative dating for lunar surfaces


LUNA Quark’s Holiday Tour LUNA Quark’s Holiday Tour

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TERRA: Unique! Quark’s Holiday Tour TERRA: Unique! Quark’s Holiday Tour

Oxygen-rich atmosphere

Over 70% surface is water

Plate tectonics recycles

oxygen and water

Only known life in Solar System (but is it intelligent?)


TERRA: Intelligence? Quark’s Holiday Tour TERRA: Intelligence? Quark’s Holiday Tour

Hope for the future:

The U-manz (Terrans) are building a space station.

- a primitive step towards exploring the universe

- people and nations who were enemies not long ago are working together.

Let’s hope they finish

growing up before

they invade us!


THAT CONCLUDES OUR TOUR Enjoy your Holiday! THAT CONCLUDES OUR TOUR Enjoy your Holiday!

Quiz 9 - 100 pts. extra credit over the locations on this tour of the solar system - will be active until 5:00 PM Wednesday Dec. 13


Documents

Quark’s Holiday Tour Part II: the Inner Planets of Sol N. Lindsley-Griffin, 1998 Mars Venus Terra Mercury Jupiter