A highland sample strategy for Pathfinder

Potential landing sites are confined to latitudes between 0 deg and 30 deg N and surfaces below 0 km elevation. The landing ellipse is 100 x 200 km oriented N 74 deg E. The constraints essentially eliminate the slopes of Elysium Mons, Olympus Mons, Tharsis Ridge, Lunae Plaunum, all the southern highlands, and almost all the Noachian material of Arabia Terra. Those areas that remain as potential landing sites are chiefly lowland plains of Amazonis Chryse, Isidis, and Elysium Planitia. Any attempt to sample highland material further constrains the possible landing sites by eliminating areas of Hesperian or Amazonian lavas and sediments. One possible sampling strategy is to sample materials within those few 'highland' terrains that extend to low elevations. A second strategy is to sample materials at the mouth of an outflow channel that drains from the highlands. Potential landing sites include outflow channel material at the edge of Chryse Planitia and highland materials bordering southern Amazonis Planitia.