MARS EXPLORATION ROVER LANDING SITE MEMORANDUM
November 20, 2001
To: MER Project, MEP and Landing Site Personnel
From: M. Golombek
Re: MER Landing Site Ellipses
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:
1.) Hematite in Terra Meridiani
ellipse 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
Geoid near center of ellipse 3395.5264 km
TM10A2 ellipse 119 km by 17 km oriented at 88 deg
TM20B2 ellipse 117 km by 18 km oriented at 86 deg
2.) Melas Chasma
ellipse VM53A2 and B2
8.88S, 77.48W MDIM2
8.75S, 282.36E MOLA
-3.70 km MOLA elevation at ellipse center
Geoid near center of ellipse 3395.7585 km
VM53A2 ellipse 103 km by 18 km oriented at 80 deg
B2 ellipse 105 km by 20 km oriented at 82 deg
3.) Gusev Crater
ellipse 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
Geoid near center of ellipse 3394.2274 km
EP55A2 ellipse 96 km by 19 km oriented at 76 deg
4.) Athabasca Vallis
ellipse 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
This ellipse could move by up to 20 km north and/or east.
Quadrilateral shows MOC image request area.
EP49B2 ellipse 152 km by 16 km oriented at 95 deg
Back Up Sites
1.) Isidis Planitia
ellipse 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
Geoid near center of ellipse 3396.1151 km
IP84A2 ellipse 133 km by 16 km oriented at 88 deg
IP96B2 ellipse 136 km by 16 km oriented at 91 deg
2.) Eos Chasma
ellipse VM41A2
13.20S, 318.46E MOLA
13.34S, 41.39W MDIM2
-3.85 km MOLA elevation at ellipse center
Geoid near center of ellipse 3394.4268 km
VM41A2 ellipse 98 km by 19 km oriented at 76 deg
