Mars Orbiter Finds Evidence Of Soviet Union Lander
April 12, 2013

Soviet-Era Mars Lander Spotted By Mars Orbiter And Citizen Scientists

April Flowers for - Your Universe Online

NASA's Mars Reconnaissance Orbiter may have captured images of hardware from a Soviet era spacecraft that landed on Mars in 1971.

Russian citizen enthusiasts were following news about NASA's Curiosity rover and Mars when they found four features in a five-year old image from the Mars Reconnaissance Orbiter. The features resemble four pieces of hardware from the Soviet Mars 3 mission: the parachute, heat shield, terminal retrorocket and lander. The orbiter took a follow-up image last month that shows the same features. The images were taken using the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter.

On December 2, 1971, the Mars 3 lander transmitted for several seconds after landing, becoming the first spacecraft to survive a Mars landing long enough to transmit anything.

"Together, this set of features and their layout on the ground provide a remarkable match to what is expected from the Mars 3 landing, but alternative explanations for the features cannot be ruled out," said HiRISE Principal Investigator Alfred McEwen of the University of Arizona. "Further analysis of the data and future images to better understand the three-dimensional shapes may help to confirm this interpretation."

The former Soviet Union launched the Mars 2 and Mars 3 missions in 1971. Both missions, consisting of an orbiter and a lander, succeeded even though the surface of Mars was obscured by a planet-encircling dust storm. Mars 2 crashed while Mars 3 became the first successful soft landing on the planet. For some unknown reasons, Mars 3 stopped transmitting after just 14.5 seconds.

Mars 3 was predicted to land at latitude 45 degrees south, longitude 202 degrees east in the Ptolemaeus Crater. November 2007, HiRISE acquired a large image of this location, containing 1.8 billion pixels of data. It would take about 2,500 typical computer screens to view the entire image at full resolution. The possible hardware pieces were found on December 31, 2012.

The largest Russian Internet community about Curiosity, headed up by Vitali Egorov from St. Petersburg, did the preliminary search for Mars 3 via crowdsourcing. Egorov created a model of what the Mars 3 hardware might look like in a HiRISE image, and the community carefully searched the enormous image. They found what appear to be viable candidates in the southern segment of the image. The shape and size of each candidate are consistent with the expected hardware, and the arrangement of the pieces on the surface is what would be expected from the entry, descent and landing sequence.

"I wanted to attract people's attention to the fact that Mars exploration today is available to practically anyone," Egorov said. "At the same time we were able to connect with the history of our country, which we were reminded of after many years through the images from the Mars Reconnaissance Orbiter."

Alexander Basilevsky, of Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, is an advisor for the online community. Basilevsky contacted McEwan to suggest the follow-up image, which was acquired on March 10, 2013. The new image was targeted to cover some of the possible hardware in color and to use different illumination angles to get a second look. Egorov and Basilevsky contacted engineers and scientists who had worked on Mars 3 to obtain more information.

The most distinctive feature in the images is the candidate parachute, presenting as an especially bright spot for this region, about 8.2 yards in diameter. The size is consistent, as the parachute would be about 12 yards in diameter if it were fully spread out over the surface. The parachute appears to have brightened in the time between the two images. This is probably due to better illumination over the sloping surface, but it is also possible that the parachute brightened because dust was removed.

According to NASA, "The descent module, or retrorocket, was attached to the lander container by a chain, and the candidate feature has the right size and even shows a linear extension that could be a chain. Near the candidate descent module is a feature with the right size and shape to be the actual lander, with four open petals. The image of the candidate heat shield matches a shield-shaped object with the right size if partly buried."