This memo corrects a number of discrepancies in the November 5 memo defining the MER landing site ellipses and adds additional data for each ellipse. Specific changes include the following corrections: 1) orientation of TM10A2, 2) length of ellipses IP84A2 and IP96B2, 3) orientation of ellipse VM41A2, and 4) MDIM2 center point of EP49B2. Additional data added include center location of EP49B2 in MOLA reference frame and the elevation of the MOLA geoid (from the center of mass of the planet) and the site near the center point of each ellipse.

• Center Locations of MER Landing Site Ellipses
  
• Ellipse size and Orientations at Opening of Launch Window
  
• Ellipse sizes are 4-7 km shorter and 3-5 degrees counterclockwise in orientation from those reported below for the close of the launch window.

  Top 4 Prime Sites

  Hematite in Terra Meridiani    (map) [may need to save link to disk for this large file]

  • TM20B2 and TM10A2 are both centered at:
  • 2.07S, 6.08W MDIM2
  • 2.06S, 353.77E MOLA
  • -1.44 km MOLA elevation at ellipse center
  • TM10A2 ellipse 119 km by 17 km oriented at 88°
  • TM20B2 ellipse 117 km by 18 km oriented at 86°
  
  Melas Chasma    (map)
  • VM53A2 and B2
  • 8.88S, 77.48W MDIM2
  • 8.75S, 282.36E MOLA
  • -3.70 km MOLA elevation at ellipse center
  • VM53A2 ellipse 103 km by 18 km oriented at 80°
  • B2 ellipse 105 km by 20 km oriented at 82°
  Gusev crater    (map)
  • EP55A2
  • Moved to west, east end of ellipse in Thyra crater
  • 14.82S, 184.85W MDIM2
  • 14.64S, 175.06E MOLA
  • -1.92 km MOLA elevation at ellipse center
  • EP55A2 ellipse 96 km by 19 km oriented at 76°
  
  Athabasca Vallis    (map)
  • EP49B2 Provisionally located at:
  • 8.92N, 205.21W MDIM2
  • 8.83N, 154.67E MOLA
  • -2.64 km MOLA elevation at ellipse center
  • Geoid near center of ellipse 3395.0957 km
  • Quadrilateral shows MOC image request area.
  • EP49B2 ellipse 152 km by 16 km oriented at 95°

  Back Up Sites

  Isidis Planitia    (map)

  • IP84A2 and IP96B2 are both centered at:
  • 4.22N, 87.91E MOLA
  • 4.31N, 271.97W MDIM2
  • -3.74 km MOLA elevation at ellipse center
  • IP84A2 ellipse 133 km by 16 km oriented at 88°
  • IP96B2 ellipse 136 km by 16 km oriented at 91°
  
  Eos Chasma    (map)
  • VM41A2
  • 13.20S, 318.46E MOLA
  • 13.34S, 41.39W MDIM2
  • -3.85 km MOLA elevation at ellipse center
  • VM41A2 ellipse 98 km by 19 km oriented at 76°