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PlanetaryGeology

Geology Colloquium

Dr. Peter Sak , Dickinson CollegeInterseismic Coupling, Quaternary Uplift Rates, and Fore Arc Deformation along the Costa Rican

Segment of the Middle American Trench

Thursday 4/26 345 snacks, 400 talk

310 White Hall

Tucker County Research Assistants

• Beau Downing & Kory Konsoer taking group out at 10:00 on Monday

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Susan Reichley, undated, Water: Life's Elixir in the Solar System, URL: www.jpl.nasa.gov/solar_system/water/water_index.html. Jet Propulsion Laboratory, National Aeronautics and Space Administration, California Institute of Technology, 4 web pages.

Light Web Based Reading Assignment for today:

Sun

Relative Size of All 9 Planets4 Terrestrial

Planets 4 Jovian Planets Pluto

http://btc.montana.edu/CERES/html/PlanetSizes/images/solars0.gif

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Distance from Sun

AsteroidBelt

Comets “Ort Cloud”Terrestrial

Planets Jovian Planets

Characteristics of Planets in Our Solar SystemTerrestrial Planets Jovian Planets

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto

Diam. 0.38 0.95 1.00 0.53 11.21 9.45 4.01 3.88 0.18

Mass 0.06 0.81 1.00 0.11 317.9 95.2 14.5 17. 0.02

Density 5.42 5.25 5.50 3.94 1.33 0.69 1.29 1.64 2.05

Moons 0 0 1 2 40 30+ 22 15? 10 0 1 2 62 33 27 13 1

Rings no no no no yes yes yes yes no

Craters many few few some no no no no yes?

Updated 2004 from NASA data & http://www.solarviews.com/eng/solarsys.htm2007 Update http://www.spacetoday.org/SolSys/Moons/MoonsSolSys.html

Characteristics of Planets in Our Solar SystemTerrestrial Planets Jovian Planets

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto

Diam. 0.38 0.95 1.00 0.53 11.21 9.45 4.01 3.88 0.18

Mass 0.06 0.81 1.00 0.11 317.9 95.2 14.5 17. 0.02

Density 5.42 5.25 5.50 3.94 1.33 0.69 1.29 1.64 2.05

Moons 0 0 1 2 40 30+ 22 15? 10 0 1 2 62 33 27 13 1

Rings no no no no yes yes yes yes no

Craters many few few some no no no no yes?

Updated 2004 from NASA data & http://www.solarviews.com/eng/solarsys.htm2007 Update http://www.spacetoday.org/SolSys/Moons/MoonsSolSys.html

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Earth

Oldest Mineral: 4.4 BYOldest Rock: 3.8 BYOldest Ocean: ~200 MYOldest Landforms: <50 MY??

Antarctic View of Earth

What will be the last evidence of human beings?

Oldest Mineral: 4.4 BYOldest Rock: 3.8 BYOldest Ocean: ~200 MYOldest Landforms: <50 MY??

Last Evidence of HumankindLeft on the Lunar Surface

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Earth’s Moon

Highlands

Mare

Major Landforms Types:

Impact Craters(Breccia)

Mare(Basalt)

Highlands (Anorthosite = Gabbro)

Lunar Surface

Mare3.1-3.8 BY

Highlands4.0-4.4 BY

Collapsed Lava Tube

Rill =

ImpactCraters

Impact Craters

Ejecta

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Large Lunar Impact Crater

Ejecta Blanket

Central Upland

Rim

Generic Terrestrial Planet History

• Accretion• Rapid Contraction, Heating, Outgassing

– Magma Ocean ~100,000,000 years Slow Contraction, Heat Loss

– Fractionation into Crust, Mantle, Core (Continued Impacts-Breccias)

• Partial Melting, Volcanoes, Plate Tectonics– Larger Planets: Active Longer

Mercury

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Venus

Sister Planets?

Not!

Two Views of Venus

Visual RADAR

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Venus Topography

Akna Mountains

Folded Mountain Belt?

200 km X 125 km

Artemis CoronaPossible Subduction Zone & Magmatic Arc

2000 km diameter

6 vertical km chasma to rim

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Maat Mons volcano & Lava Flow

Venus Landscape on an Impossibly “Clear” Day

Domes Near Alpha Regio

25 km diam.750 m high

http://www.astronomical.org/planets/jpeg/ven/pancakes.jpg

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Wind Streaks

35 km long

Volcano =5 km diam

Mead Crater Wind Streaks

Surface From Venera 13

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Mars

VallisMarinaris

Mars Topography

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Map of Martian Impact Craters >100 km Diameter

Martian Surface Ages

Noachian3.85-4.6 by

Amazonian 0-1.8 by

Hesperian1.8-3.85 by

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Cratered Highlands

Cratered HighlandsSame Imaged, But Rotated to Show Shadow Effect

Mass Wasting

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Tyrrhena Petera

Ceraunius & Uranius Tholi

Ulysses Patera

Volcanowith

Impact Craters

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Ulysses Patera

Mars Topography

TharsisVolcanoes

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OlympusMons

Solar System’s Largest Volcano

Basaltic? Shield Volcano

Polar “Ice”

Sheet

Map of Channels

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Dendritic Channels

Martian Meanders

Gullies in Nirgal Vallis, Mars

Next Slide: Source Info & Discussion by Malin Science

Center

JSK: Debris Flow or Avalanche Tracks Feeding Debris Cones that

Lap Over Megaripples

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Gullies in Nirgal Vallis, MarsMars Global Surveyor Mars Orbiter Camera

Release No. MOC2-535, 5 November 2003http://images.google.com/imgres?imgurl=http://antwrp.gsfc.nasa.gov/apod/image/0006/marsnewton_mgs_big.jpg&imgrefurl=http://www.astro.cz/apod/ap000626.html&h=797&w=1067&sz=225&tbnid=bxX4Emk9ttgJ:&tbnh=112&tbnw=150&start=33&prev=/images%3Fq%3Dwater%2Bon%2BMars%26start%3D20%26hl%3Den%26lr%3D%26sa%3DN

• This is a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) narrow angle image of gullies carved into debris on the south-facing wall of Nirgal Vallis, an ancient martianvalley. The gullies were conduits for sediment that has accumulated at a point where each channel met the valley floor. The aprons of debris are superposed upon the large ripple-like dunes, suggesting that the gullies are younger than these bedforms. Gullies such as these might have been formed by a liquid, such as water, seeping from the layered bedrock exposed in the valley wall, or perhaps by mass movement of the smooth-surfaced debris that covers much of the lower two-thirds of the valley wall. Image is located near 28.6°S, 41.5°W, and covers an area 3 km (1.9 mi) across, illuminated by sunlight from the upper left.