Chuck Bednar for redOrbit.com – Your Universe Online
Photos taken by NASA’s Curiosity rover may contain the first visual evidence that life could once have existed on Mars, a geobiologist from Old Dominion University in Virginia claims in research recently published online by the journal Astrobiology.
According to NBC News, Dr. Nora Noffke, an associate professor in the Department of Ocean, Earth and Atmospheric Sciences, found “intriguing similarities” between ancient sedimentary rocks on the Red Planet and structures on Earth that had been shaped by microbes. The findings suggest, but do not prove, that such life may also have existed on Mars.
The pictures were taken by Curiosity as it drove through the Gillespie Lake outcrop in a dry lakebed known as Yellowknife Bay. This region apparently underwent seasonal flooding several billion years ago, when the Red Planet was a far warmer and wetter planet, the explained.
“We can detect sedimentary structures in rocks on Mars using the rover images,” Dr. Noffke explained during an email interview with The Huffington Post. “The structures I describe belong to a group of microbial structures that form by the interaction of benthic (living on the ground) microbes with sediment dynamics (erosion) in clastic deposits such as sand.”
If these structures do exist on Mars, it would suggest that the planet could once have harbored microbial life, and that those microbes would have existed there less than 3.7 billion years ago. Noffke analyzed the structures, comparing them to the so-called microbial mats found on Earth, and detailed the similarities between the structures found on both Earth and Mars.
“The microbially induced sedimentary-like structures (MISS) identified in Curiosity rover mission images do not have a random distribution,” she wrote. “Rather, they were found to be arranged in spatial associations and temporal successions that indicate they changed over time.”
“On Earth, if such MISS occurred with this type of spatial association and temporal succession, they would be interpreted as having recorded the growth of a microbially dominated ecosystem that thrived in pools that later dried completely,” the researcher added, going on to propose “a strategy for detecting, identifying, confirming, and differentiating possible MISS during current and future Mars missions” in her recently-published study.
While Noffke’s proposes a hypothesis for the possible signs that life existed on ancient Mars, NBC News pointed out that her findings are not concrete evidence that those structures were formed an shaped by biological entities. Such confirmation would require collecting rock samples and bringing them back to earth for microscopic analysis.
No such mission is currently on the schedule in the foreseeable future
“The fact that she pointed out these structures is a great contribution to the field,” Penelope Boston, a geomicrobiologist at the New Mexico Institute of Mining and Technology, told NBC News. “Along with the recent reports of methane and organics on Mars, her findings add an intriguing piece to the puzzle of a possible history for life on our neighboring planet.”
Dr. Chris McKay, a planetary scientist at NASA’s Ames Research Center and associate editor of Astrobiology, said that the research was promising, according to the Huffington Post.
“I’ve seen many papers that say ‘Look, here’s a pile of dirt on Mars, and here’s a pile of dirt on Earth, and because they look the same, the same mechanism must have made each pile on the two planets,’” he said. “That’s an easy argument to make, and it’s typically not very convincing. However, Noffke’s paper is the most carefully done analysis of the sort that I’ve seen.”
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