1. Introduction to Planetary Geology Patricio Figueredo PSF 571 figueredo@asu.edu Patricio Figueredo PSF 571 figueredo@asu.edu

2. Planetary geology Magellan Galileo MGS Odyssey MER rovers Mars Express

3. 1) the Solar System PlanetaryGeology Planets make up ~ 0.15% of our Solar System’s mass Sun accounts for the other 99.85%!

4. The Solar System of Planets

5. Overview of Planets Overview of PlanetsPlanetaryGeology The planets’ composition changes with distance to the Sun Venus Mercury Earth Mars Jupiter Saturn Uranus Neptune Pluto Sun terrestrial planets (mostly rock & metallic) Gas Giant planets (H, He) w/ rock/ice satellites

6. Satellites are worlds in their own right!

7. Mercury u No atmosphere, lots of craters u Looks like our Moon u Mercury day takes 6 months! u only half of it is known

8. Venus u Earth-like size, density u covered in thick clouds u surface very hot 900 o F! u recent volcanism and tectonics u Earth-like size, density u covered in thick clouds u surface very hot 900 o F! u recent volcanism and tectonics

9. Earth GEOLOGIC PROCESSES: tectonism volcanism gradation impact cratering

10. tectonism volcanism gradation

11. Impacts!!!

12. mess cars cause extinctions knock trees scar planets!

13. Impact craters on Earth

14. PlanetaryGeology Meteor Crater, AZ

15. Impact origin of the Moon!

16. the Moon PlanetaryGeology Unusual…. Moon is large for a planet “moon” Its density is ~ 3.3 gm/cm 3 … This is close to Earth crustal rocks Gravity on Moon is 1/6 that on Earth

17. the Moon PlanetaryGeologymariahighlands maria - large basalt flows highlands - cratered old crust regolith - unconsolidated rock & dust layer

18. Mars half Earth’s size two small moons canyons, volcanoes, etc.

19. Canyons!

20. Volcanoes! huge shield volcanoes flood plains

21. Mars water!!

22. ASU discovery: Mars gullies’ smoking gun

23. on the news: The Mars Exploration rovers

24. Last Saturday: Opportunity landed!

25. Jupiter u Largest planet in the Solar system u giant storm systems u (2 Earths fit in red spot) u 62 moons!!!

26. u Io u Europa u Ganymede u Callisto Geologic targets

27. Io Volcanically active! 8 or more volcanoes erupting at any given time

28. Europa ocean of salty water under the ice! (~2 Earth oceans!!)

29. u composition similar to Jupiter, but twice as far from Sun u Most extensive ring system u Atmosphere winds: 930 m.p.h.! u At least 21 moons Saturn

30. Titan only satellite with atmosphere! organic (C) compounds lakes of liquid methane, H Cassini (07/04)

31. Uranus u Methane atmosphere (blue) u Rotates on its side u At least 15 moons

32. Miranda unique terrain!! huge extensional systems 16 km cliff!!

33. Neptune u Also methane atmosphere u Great dark spot and White clouds u 8 known moons

34. Triton cantaloupe terrain fissures, pools active giant geyser eruptions!!

35. Pluto / Charon u binary system u 248 Earth years to go around Sun once u Charon, its moon, is over half Pluto’s size u only unexplored planet

36. 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