36. Mars Pathfinder Landing Site
The Mars Pathfinder spacecraft landed near the center of this ellipse, as planned, on July 4, 1997. The ellipse is the original target area, 300 kilometers long and 200 kilometers wide. Mars Pathfinder landed only 50 kilometers from the ellipse center. This landing site is outside the mouth of the huge water-cut channel of Ares Vallis (19.33°N, 33.55°W) that empties into the lowlands of Chryse Planitia near the Viking 1 lander site. At its landing site, Pathfinder and its rover were able to see and analyze rocks that were washed down Ares Vallis during its floods. These rocks could come from the ancient southern highlands and from plains that are huge basalt lava flows.
This landing site was chosen in April 1994, when 60 scientists gathered at the Lunar and Planetary Institute in Houston. Their goal was to find sites where Mars Pathfinder could land and survive (flat surface, low elevation, latitude between 5° and 20°N), and return important information. Each scientist had a favorite site, and the Pathfinder program managers considered them all. Ares Vallis was chosen because it seemed relatively safe (flat and low), was known fairly well (the Viking spacecraft had taken detailed images of the area), and probably would provide important rock samples for Pathfinder to view and analyze.
Composite Viking images, NASA/JPL