Shortly after NASA's Mars Polar Lander (MPL) entered the Martian atmosphere on December 3, 1999, the spacecraft disappeared without a trace. Almost immediately, scientists began looking for the missing lander with the Mars Orbiter Camera (MOC) aboard NASA's Mars Global Surveyor. But searches conducted in 1999 and 2000 by MOC's head scientist, Michael Malin (Malin Space Science Systems), found nothing.
Earlier this year, using information gained from observing the two Mars Exploration Rovers, Malin reexamined the older images looking for similar features. This time he identified what looks to be a parachute located several hundred meters away from a disturbed bit of ground with a large mark in its center. The parachute-like feature closely matched the Mars Exploration Rover parachutes (which were made of the same materials), and Malin believed the disturbed ground matched what one would see if a rocket had blasted the surface from a height of tens of meters the final phase in the MPL touchdown maneuver. In the center of the disturbed ground was a notable mark presumably the missing lander.
The case was far from closed, however. More observations were needed to conclusively identify the missing lander. So MOC reexamined the scene on September 27th under nearly identical lighting conditions. Unfortunately the follow-up observations came up empty the feature thought to be the lander was gone. Malin and his team conclude that the mark they saw in the older image was noise in the data.
Malin says that MOC will no longer look for MPL. Any future searches will be conducted by the Mars Reconnaissance Orbiter's HiRISE instrument, which can return images of the surface as detailed as 1 meter per pixel after it arrives at the Red Planet in March 2006.