Citizen scientists in Russia may have identified the remains of a long-lost Soviet lander on Mars by poring over photos of the surface taken from the Mars Reconnaissance Orbiter with the University of Arizona's HiRISE camera.

Alfred McEwen, principal investigator for HiRise and a professor of planetary sciences at the UA's Lunar and Planetary Laboratory, said the features revealed in the HiRise image make them "a very intriguing candidate" for being the Mars Lander 3, which made the first successful soft landing on Mars in 1971 but stopped communicating 14.5 seconds after its touchdown.

NASA and the UA team that runs HiRISE from an office on campus acquired a second photograph of the suspected lander after being contacted by Russian scientist Alexander Basilevsky, on behalf of a Russian Internet community that had linked computers to "crowd-source" a search of large photos taken by HiRISE near where the craft had landed, McEwen said.

HiRISE took a new image in color, with different illumination angles, on March 10. It showed features that can be interpreted to show a parachute, a chain, a descent module, a heat shield and the lander itself, McEwen said.

There could be other explanations for the appearance of those features on the surface of Mars, but he is "51 percent convinced" that the image shows the lander.

"It's plausible," he said, "but you can come up with natural explanations for each individual feature."

Contact reporter Tom Beal at or 573-4158.