1. Planetary Surfaces III
Where
is this?

2. Io Map
density is 3.53 g/cm3, similar to Moon at 3.34 g/cm3 … mostly rock
not a single crater found … surface less than a few Myr old
surface covered with SO2 frost
light areas are sulfur compounds … dark areas are pyroxene and olivine
red ring from Pele (?) via polymeralization of S2 … fades over months, so must be recent

3. Galileans
3.53 g/cm g/cm g/cm g/cm g/cm g/cm3
rocky
active
volcanoes
calderas
rocky
H2O ice
floes
ridges
lenticulae
dirty ice
craters
palimpsests
grooves
light/dark
areas
icy-est
craters
palimpsests
lenticulae = “freckles” from convective upwelling of warm ice, like lava lamps

4. Titan Map from Cassini 2007 imaged at 9380 A
density is 1.88 g/cm3 … part rock, part ice
few craters … surface less than 1 Gyr old
liquid CH4/C2H6 lakes near poles cover ~1% of surface and change size
imaged at 9380 A

5. Titan Map from Cassini 2011 imaged at 9380 A
density is 1.88 g/cm3 … part rock, part ice
few craters … surface less than 1 Gyr old
liquid CH4/C2H6 lakes near poles cover ~1% of surface and change size
imaged at 9380 A

6. Titan Map from Cassini 2015 imaged at 9380 A
density is 1.88 g/cm3 … part rock, part ice
few craters … surface less than 1 Gyr old
liquid CH4/C2H6 lakes near poles cover ~1% of surface and change size
imaged at 9380 A

7. Titan: Xanadu Xanadu rough surface bright in radar 5 km wide
active riverbeds with CH4, or dry arroyos? unknown
resolution ~ 1 km
rough surface
bright in radar
5 km wide

8. Titan: 70deg N Titan: 70deg N
Xanadu
(M)Ethane Sea?

9. Titan Close Up

10. Iapetus albedo ~ 0.60 albedo ~ 0.04
dark region is leading hemisphere … organics including HCN-polymers … likely extra-Iapetus origin
ridge is 20 km wide

11. Mimas

12. Miranda
5 km
high
D =
470 km
> 1%
… 127 km
on Earth!

13. Tethys and Enceladus Tethys and Enceladus
Tethys much more distant … note that it’s lit up by Sun/Saturn

14. Triton 2.05 g/cm3 N2/CH4 ice cantaloupe terrain (repeated fracturing)
N2 geyser
plumes

15. But Wait, There’s More …
We’ve talked about a bit We’ve barely mentioned
Venus Mercury
Earth Moon
Mars Europa (more later)
Io Ganymede
Titan Callisto
Enceladus (more later)
Iapetus
Mimas
Miranda
Triton
In a longer course, we’d also talk about Pluto
Amalthea reddest object in Solar System + some green
emits more heat than it receives from Sun
Hyperion The Sponge … with density 0.6 g/cm3
Amalthea: red from Io’s sulfur … green unknown … heat from electric currents in core or tidal stresses?

16. Solar System Explorers 08
Name a location in the Solar System where surface processing is occurring.
Each process can be used only once. Describe how that surface is being
reprocessed, e.g. Earth’s land mass coastlines change because of liquid H2O.
1. Io volcanism deposits magma
2. Earth/Mars dust dunes due to wind
3. Venus has solid state creep due to high T/P
4. Mars CO2 deposition/sublimation cycle
5. Titan liquid CH4 rain
6. Venus pancake domes due to magma bubbling
7. Earth land smoothing via volcanic flows
8. Earth has mountain building via orogenesis from plate tectoncis
9. Venus dunes caused by wind
10. Enceladus has plumes and tiger stripes
11. Galilean moons suffer BUTTCIALS!
12. Earth has H2O subsides Antarctica
13. Moon suffers lunar flash events that create new craters
14. Pluto has cryovolcanism
15. Mercury has tectonic scarps in abundance because of shrinkage
16. Earth has continental outlines because of plate tectonics
17. Europa has ridges because of shifting hard/soft H2O ice
18. Earth organics change the color of the surface, change albedo
19. Triton has N2 magma
20. CRATERS HAPPEN.

17. Solar System Explorers 09
Describe an observation that yields information about a particular world’s interior, e.g. seismic data on Earth tell us that the size of the solid core is 1200 km.
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