Washington

Scientists operating the Mars Orbiter Camera have spotted a pair of long-lost spacecraft — the Viking Lander 2 and Mars Polar Lander — in pictures taken from martian orbit. They hope that the pictures of Mars Polar Lander can provide clues to how and why the spacecraft crashed.

Figure 1
figure 1

NASA/JPL/MSSS

Spotted: to the trained eye, this image looks just like Viking 2.

Full size image

The Mars Orbiter Camera has been circling the planet since 1997. Researchers at Malin Space Science Systems of San Diego, California, who built the camera with the California Institute of Technology, are fairly sure about the identification of Viking 2, which has been sitting on the surface since 1976. But confirmation for the polar lander, which is thought to have crashed when its braking rockets shut down prematurely during its landing in 1999, will have to await sharper photos. Principal investigator Michael Malin hopes to begin taking those by late July, once frost on the martian surface has cleared up.

Malin has photographed other Mars landers from orbit, including Viking Lander 1, Mars Pathfinder and the two current Mars Exploration Rovers. But the panoramic photos from Viking 2, which landed on a plain called Utopia Planitia, showed a flat and featureless terrain with few landmarks to help nail down where to look for it. Until now, the location was known only to within a few kilometres.

The picture believed to show the Mars Polar Lander was taken in 2000, although it was impossible to identify it at the time. Since then, photographs of the Mars rovers have given Malin a better idea of how parachutes and dark soil churned up by rocket blast would look from orbit.

So far, though, Malin hasn't found anything in his pictures that looks like the small Beagle 2 lander lost in 2003. And until he has such a candidate, high-resolution searching of the surface would be like looking for a needle in a haystack.