After being lost and potentially found, NASA’s Mars Polar Lander appears to be lost once more.

The sharp-shooting Mars Global Surveyor has repeatedly scanned for wreckage of the Mars Polar Lander (MPL), which disappeared on touchdown in December 1999.

Camera specialists at Malin Space Science Systems (MSSS) near San Diego, California initially thought they might have spotted the probe’s parachute, as well as disturbed terrain from the craft’s landing engines.

But comparative imagery of the same location taken in January 2000 and September 2005 provide “excellent evidence” that possible spacecraft components are “not real features on the surface of Mars,” a new posting on the MSSS web site explains.

The pictures were taken several Martian years apart under nearly identical illumination and atmospheric conditions, but the feature once identified as a candidate for MPL’s parachute turned out to be the illuminated slope of a small hill, while the dark feature suggesting a rocket blast zone has faded – which would be expected owing to dust deposited by dust storms. But more importantly, the spot interpreted to be the lander has disappeared altogether, the MSSS site points out.

 “We conclude that our interpretation of these features was in error. This is not the location of the Mars Polar Lander. Because the landing uncertainty ellipse is so much larger than our images, and we do not have another candidate to which to target…we cannot continue to hunt for the lander,” the MSSS site explains. “Finding it now falls to the High Resolution Imaging Science Experiment (HiRISE) presently en route to Mars onboard the Mars Reconnaissance Orbiter (MRO) spacecraft.”

• X Marks the Spot? Possible Landing Site of Mars Polar Lander Identified

-- Leonard David

Credit: NASA/JPL/Malin Space Science Systems.