Post on 22-Dec-2015
Introduction toIntroduction toPlanetary GeologyPlanetary Geology
Patricio FigueredoPSF 571
figueredo@asu.edu
Patricio FigueredoPSF 571
figueredo@asu.edu
Planetary geology
Magellan
GalileoMGS
Odyssey
MER roversMars Express
1) the Solar System1) the Solar SystemPlanetaryPlanetaryGeologyGeology
Planets make up ~ 0.15% of our Solar System’s massSun accounts for the other 99.85%!
The Solar System of Planets
Overview of PlanetsOverview of PlanetsPlanetaryPlanetaryGeologyGeology
The planets’ composition changes with distance to the Sun
Ven
us
Mer
cury
Ear
thM
ars
Jupi
ter
Sat
urn
Ura
nus
Nep
tune
Plu
to
Su
n
terrestrialplanets(mostly rock & metallic)
Gas Giant planets (H, He)w/ rock/ice satellites
Satellites are worlds in their own right!
Mercury
No atmosphere, lots of craters Looks like our Moon Mercury day takes 6 months! only half of it is known
Venus
Earth-like size, density covered in thick clouds surface very hot 900 oF! recent volcanism and tectonics
Earth-like size, density covered in thick clouds surface very hot 900 oF! recent volcanism and tectonics
Earth
GEOLOGIC PROCESSES:•tectonism •volcanism•gradation•impact cratering
tectonism volcanism
gradation
Impacts!!!
mess cars
cause extinctions
knock trees
scar planets!
PlanetaryPlanetaryGeologyGeology
Meteor Crater, AZ
Impact origin of the Moon!
the Moonthe MoonPlanetaryPlanetaryGeologyGeology
Unusual….Moon is large for a planet “moon”
Its density is ~ 3.3 gm/cm3… This is close to Earth crustal rocks
Gravity on Moon is 1/6 that on Earth
the Moonthe MoonPlanetaryPlanetaryGeologyGeology
mariamaria
highlandshighlandsmaria - large basalt flows
highlands - cratered old crustregolith - unconsolidated rock & dust layer
Mars
•half Earth’s size•two small moons•canyons, volcanoes, etc.
Canyons!
Volcanoes!
•huge shield volcanoes•flood plains
Mars water!!
ASU discovery: Marsgullies’ smoking gun
on the news: The Mars Exploration rovers
Last Saturday: Opportunity landed!
Jupiter
Largest planet in the Solar system
giant storm systems
(2 Earths fit in red spot)
62 moons!!!
Io
Europa
GanymedeCallisto
Geologic targets
Io
Volcanically active!
8 or more volcanoeserupting at anygiven time
Europa
ocean of salty water under the ice! (~2 Earth oceans!!)
composition similar to Jupiter, but twice as far from Sun Most extensive ring system Atmosphere winds: 930 m.p.h.! At least 21 moons
Saturn
Titan
•only satellite with atmosphere!
•organic (C) compounds
•lakes of liquid methane, H
Cassini (07/04)
Uranus Methane atmosphere (blue)
Rotates on its side
At least 15 moons
Miranda
•unique terrain!!
•huge extensional systems
•16 km cliff!!
Neptune
Also methane atmosphere
Great dark spot and White clouds
8 known moons
Triton
•cantaloupe terrain
•fissures, pools
•active giant geyser eruptions!!
Pluto / Charon
binary system
248 Earth years to go around Sun once
Charon, its moon, is over half Pluto’s size
only unexplored planet
Some key points
• 4 geologic processes: tectonism, volcanism, gradation,
impacts
• Mercury resembles our Moon, and is inactive
• Venus has thick atmosp., high T, and recent volcanism and
tectonics
• Earth is an active planet, driven by plate tectonics
• Mars has huge volcanoes and canyons. Water was stable in
the past.
• Jupiter’s Io is the most volcanic body in the Solar System
• Jupiter’s Europa is prob. active, could have an ocean of salty
water
• Saturn’s Titan has a thick atmosphere and organic
compounds
• Uranus’ Miranda has enormous extensional faults and cliffs
• Neptune’s Triton has active geysers
• Pluto and Charon form a double-system and remain
unexplored
• Apart from Earth, only Mars, Europa, Titan, and prob. Triton have some potential for astrobiology