Viking Lander 2
One of the more interesting and appealing activities of the Mars Orbiter Camera (MOC) observational objectives identified in the original 1985 Mars Observer proposal was to image landers on the martian surface. The scientific goal of this objective is to place the landers into their geologic context, which in turn helps the science community to better understand the results from the landers. In addition to this, the MOC team believed that it would be "really neat" to see the landers sitting on the surface. In previous releases, we have shown images of Viking Lander 1, Mars Pathfinder, and the two Mars Exploration Rovers, Spirit and Opportunity. To this group of landers we can now add with certainty Viking Lander 2 (VL-2), the location of which has been uncertain by many kilometers for nearly 30 years.
The first figure (above) shows: (A) a mosaic of Viking Orbiter images obtained in the 1970s at a resolution of 75 m/pixel, (B) a typical Mars Global Surveyor (MGS) MOC narrow angle camera view at about 3 meters/pixel (25x higher resolution than the Viking images), and (C, D) sections of a cPROTO image at 0.5 m/pixel.
Finding Viking 2 has been a challenge owing to the extreme subtlety of horizon features visible in the lander panoramas and relatively inaccurate radio tracking data. Without the diligent work of Timothy J. Parker of the Jet Propulsion Laboratory and Philip Stooke of the University of Western Ontario, we wouldn't really have known where to point the MOC. Using the best estimated locations based on sightline studies to guide our targeting, we finally located the lander amid the remarkably homogenous terrain. Viking Lander 2 touched down on Utopia Planitia on 3 September 1976.