1. Mars

5. Moons of Mars

6. Exploration of Mars ~1800: Herschel and others discover ice caps and clouds 1877: Phobos and Deimos discovered; also Schiaparelli (It.) refers to ‘canali’ 1890’s: Lowell interprets markings as canals, implying intelligent Martian life 1965 Jul: 1 st close-up photos by Mariner 4 1971 Nov: 1 st orbital probe in Mariner 9 1976 Jul: Viking 1 lander – no life 1997 Jul: Mars Pathfinder 1997 Sept: Mars Global Surveyor 2001 Oct: Mars Odyssey 2004 Jan: Spirit (Rover) 2006: Mars Reconnaissance Orbiter 2007: Phoenix lander

7. Martian Travel Brochure

8. The Martians are Coming!

9. Percival Lowell’s Martian “Canals”

10. Lowell’s Surface ID’s

12. Properties of Mars Iron core of 1500 km in radius Low magnetic field (about 0.1% of Earth’s), because molten core has largely cooled Resurfacing from past volcanic activity Polar caps of dry ice No surface water Thin CO 2 atmosphere Red coloration from oxidized iron minerals

13. Views of Mars

15. Principal Surface Regions

18. Impact Aided Atmospheric Losses?

19. Crater Distribution at Mars

20. Olympus Mons

21. The Face at Mars

22. Martian Terrain: Dunes

23. Victoria Crater

24. Cape Verde

25. Dry River Beds and Channels

26. Run-Off of Water?

27. Water on Mars Evidence for channels and sea beds (?) H 2 O in clouds and polar caps, but only trace Mars Odyssey implies subsurface water ice So maybe Mars warmer and wetter in past (even oceans?), and perhaps a lot of that water exists as permafrost below the surface (although in a warmer Mars, water vapor is close to escaping low gravity of Mars)

28. Looking for Water

30. Ocean Beds at Mars?!

31. Methane in the Martian Atmosphere Methane gas was recently detected in Mars’ atmosphere using groundbased telescopes The methane gas distribution is patchy and changes with time Most methane in Earth’s atmosphere is produced by life, raising questions about its origin on Mars View of Mars colored according to the methane concentration observed in the atmosphere. Warm colors depict high concentrations.

32. Recent Release of Methane Methane in the atmosphere should be destroyed by UV light within a few hundred years Methane observed now must therefore have been produced recently Variations in space and time suggest that it was recently released from the subsurface in localized areas UV photons have enough energy to break molecules apart

33. The Big Picture Where can the methane come from? From analogy with Earth, there are two leading theories for the origin of recent subsurface methane at Mars: 1.Methane is produced by water- rock interactions 2.Methane is produced by bacteria, in regions where liquid water is found Either theory implies that the Martian subsurface is dynamic However, Curiosity has so far FAILED to detect any methane Methane on Mars could be produced chemically through liquid/rock interactions (top) or biologically (bottom) methane liquid water hot rock surface methane bacteria ~2 µm

34. Martian Weather 1)Mars tilt like Earth, hence similar seasons 2)Mars has e~0.1, so 10% closer at perihelion and 10% farther at aphelion  S. summer is warmer, receiving 50% more light compared to N. summer  Dust storms: greater heating in S. leads to more convection and lifting of dust; storms can last for several weeks

35. Understanding Seasons at Mars

36. Martian Skies

39. Evolution of the Polar Caps

41. Terrestrial Atmospheres  Terrestrials have secondary atmospheres, which are produced by outgassing from the planet interior  Comets have likely influenced our atmosphere, possibly supplying some water for oceans during early bombardment era Atm.Oceans Mercury---N Venus Massive CO 2 N EarthN 2, O 2 Y Mars Thin CO 2 N

42. Some Details… oDetails of Outgassing: volcanos yield mainly CO 2 and H 2 O oComparative Planetology: Venus and Mars have CO 2 atmospheres, but not Earth, but Earth has oceans, so that the CO 2 is in carbonate rocks oWhy O 2 at Earth? Photosynthesis from plants. Earth O-poor until 2.5 Gyrs ago, and earliest plant fossils are 2 Gyrs old oWhere did H 2 O go at Venus? Break up molecule and H 2 escapes

44. Interaction of CO 2 and Water

45. Atmospheres and Phase Diagrams

46. Changes in the Earth Atmosphere