Exam 2 Flashcards
Mercury Terrain
Heavily cratered, inter-crater plains, scarps, caloris basin, smooth plains, antipodal (opposite side) “weird terrain”
MESSENGER
Visited Mercury, shows huge partly liquid core, maybe ice deposits at poles
Venus Terrain
Highlands and lowlands… was there a giant cataclysm 500 million years ago? or was it resurfaced some other way?
Venus Geological Activities
Volcanoes include shields, domes, and pancakes (different lava viscosity).
No evidence of plate tectonics, but local tectonic features
Venus future exploration
Fly or land, take pictures, sample rocks, look for venus quakes
Mars Terrain
cratered south and volcanic north, Giant canyons (Valles Marineris)
Mars Geological activities
Giant volcanos (Olympus Mons). Tectonic extensions created Valles Marineris.
Mars evidence of past water
rampart craters, dendritic channels, tear-shaped islands, deltas, gullies
Mars atmosphere
early thick atmosphere provided greenhouse, but now it is lost (giant impact? stalled tectonics, or solar wind stripping because mag field left when core froze)
MER
aquatic minerals, multiple stages of wet dry; bluberries
Phoenix
excavated ice under surface, plygon surface shows freeze-thaw cycle
MSL
shows gravel bed (stream beds), conglomerates
Life on Mars
None apparent yet
Where to look for life on other planets
Follow the water, methane gas (possible bio-signature), Look for fossils in hot springs or lakebeds or permafrost
Planetary Protection
Protect mars from earth contamination or vice versa
Comparitive Planetology
- suffered late heavy bombardment,
- early stage of basaltic volcanism,
- smaller planets have cooled and are now geologically dead.
- Maria indistinguishable (moon, mercury, mars)
- venus, earth were similar when life arose
How many worlds orbit the Jovian planets?
more than 170
What makes the jovian moons active?
Tides and orbital resonances
What moons have erupted water?
Europa, Ganymede, Enceledus
What causes Jovial moon volcanic activity
Orbital resonances -> elliptical orbit -> tital heating -> volcanoes
Where to look for life on jovial moons?
Underground oceans… most like earth conditions
How many moons does saturn have?
62+
What is the source of Saturn’s E ring
Enceladus erruptions
What might have been captured from the Kuiper Belt?
Phoebe
Titan
- methane clouds, rain, streams, lakes
- Nitrogen atmosphere (1.5 bar)
- Underground reservoirs and aquifers
- Too cold for life as we know it (but may be like early earth)
- surface dunes and intermittent streams
How many moons does uranus have?
21
Miranda
Uranus - Cliffs indicate reassembled satellites
Cordelia and Ophelia
Uranus - sheppard the largest Uranian ring
Triton
Neptune - retrograde orbit, likely captured
Cantaloup terrain, flood plane, wind streaks
Icy Satellites
Active because of tides, ice melts easier than rock
Rocky cores with icy (liquid?) mantels, Icy cratered crust
Volcanically active moons
Io, Enceladus, Triton
circumference of sphere
2(pi)R
surface area of sphere
4(pi)R^2
single plate tectonic resurfacing time eq
T = circumference / rate
multiple plate tectonic resurfacing time eq
T = circumference / (number of plates * rate)
Volcanic resurfacing rate equation
R = num of volc * rate / surfarea
Why is permanent polar cap a good place to look for life?
it is made of water/ice
Why is under the surface a good place to look for life?
Permafrost is a water source
Why ar Geothermal Areas a good place to look for life?
Can melt ice to make water
Why are Ancient streams and lake beds a good place to look for life?
Were once wet, look for fossils
Pressure equation
P = Mass * g / Surfarea
density of water
1g/cm^3 (or 100kg/m)
Bar to STI
1 Bar = 1kg/(s^2 * m)
Mariner
channels, rampart craters
Viking
water frost on cold mornings, permanent H20 cap
Mars Pathfinder
tumbled rocks
Mars global surveyor
gullies, channels
