• 2 high-resolution color CCDs (4000 x 24,000 pixels)
• 360° pan, 180° vertical
• 9 ounces each
• filter wheel for each eye -- multispectral imaging

• shaped like sundial, located on rover deck
• colored corners
• shadows -- adjust brightness

• combination microscope and CCD (1024 x 1024 pixels)
• broad band filter, black and white images
• small-scale features -- grain shape and size

• two grinding wheels
• 2 inch diameter, 0.2 inches deep

• IR spectrometer
• identify minerals and abundance based on patterns of thermal radiation
• 5 pounds, located in body of rover
• mirrors on rover neck send light down, same view as PanCam

• specialized for iron-bearing minerals
• measures composition and abundance very accurately
• one measurement takes ~12 hours

• small alpha particle source
• alphas hit target, excite X-rays
• energy distribution of alphas and X-rays -- elemental composition
• one measurement takes ~10 hours

• outcrops flush with crater wall or protrude ~50 cm
• fine grained dirt
• high albedo yellow-red outcrop

• static conditions

• fluid transport causes angled laminae

• festoon (concave) geometry indicative of subaqueous formation
• shallow water causes crested ripples

• type and scale of cross-lamination known to form in presence of flowing water, not other fluids (wind)
• ripples as deep as 5 cm; estimated water speeds 10-50 cm/s

• MB: jarosite
• APXS: sulfur
• Mini_TES: substantial Mg and Ca sulfates, 20-40% by weight

sulfur in Mg,Ca salts  +  sulfur in jarosite  =  total amount of sulfur detected

• Sulfates are hydrated compounds (contain hydroxyl, OH); likely formed in the presence of water
• Terrestrial rocks with lots of salt either formed in water or were greatly altered by long term exposure to water after formation
• Source of H atoms detected by Mars Odyssey Gamma-Ray Spectrometer

• Isolated concentrations of Br
• Br is more soluble in water; higher dissolved abundance
• High Br to Cl ratios found in evaporite deposits on Earth

• Gray spherules found embedded in outcrop and loose on ground
• PanCam measures different visible and near IR spectral properties
• Different composition from rocks in outcrop

• Diameters 4-6 mm
• Most spherules are single; some "doublets" and "triplets" were observed
• Few deviations from perfectly spherical
• Roughly 2% of the rock by volume

• Spherules too small for AXPS or MB to directly determine composition
• Mini-TES: fraction of field of view filled by spherules matches measured concentration of hematite
• MB: strong hematite signal at Berry Bowl compared to signal at adjacent outcrop lacking spherules
• APXS: very high concentrations of Fe at Berry Bowl

• RAT:
  • polished smooth, no internal structure
  • harder than rest of rock, resist erosion
  • grinding causes red color
  
  
• PanCam:
  • consistent spectral properties throughout
  • solid hematite, not just surface coating

• Main constituents of gray hematite detected by MGS TES
• Hematite not strictly in spherules; small concentrations found elsewhere
• Not concentrated along strata; formed where they are found
• Formed early in lithification in standing water
  • on Earth, gray hematite only known to form in standing water or hot springs
• Minerals came out of solution as water diffused through rock: concretion

• Cavities inside rock
• 5% of surface area
• Size increases slightly with depth; chemical process, not physical
• Crystals grow inside rock and later erode, leaving void
• Common scenario: salt crystals form in rocks soaked in salty water; crystals later dissolve in less concentrated water

• Rock layers
• Minerals (sulfates, gray hematite)
• Vugs

• Repeated cycles of flooding, evaporation, desiccation, erosion
• Acqueous transport (festoon pattern)
• Cements and concretions
• Mineral dissolution and vugs
• Planar, low-angle lamination
• Time and duration of water uncertain
  • Meridiani plain - Noachian Era (3.5 billion years ago)

• Meridiani Planum might have been habitable at some time in the past, but...
  • Precipitating waters usually acidic
  • Sulfates indicate high salinity
  • Extremophiles on earth live in those environments, but they didn't originate in them
  
  
• Wet environment might have been widespread over a long time, but...
  • Discontinuous periods of water
  • Origin, evolution unlikely

• Mars Global Surveyor
• Deposits several hundred meters long
• Liquid water
• Surface frost/ice
• Salty crust