The Curiosity rover on Mars has spotted an unusual feature, resembling ancient fossilized formations on the surface of the Red Planet. However, it is still uncertain if patterns seen in the structure spotted on the alien world were formed by alien life.
Curiosity spotted patterns in rocks on the Martian surface which resemble those created by microbes here on Earth. The images were recorded in rocks from an ancient lake bed inside Gale Crater, where the spacecraft has spent much of its time since landing.
Methane spikes recently recorded on Mars may have been created by organic chemicals. If the newly-recognized patterns are fossils, the two discoveries together may indicate that life once existed on the planet.
Patterns of sediments on Earth can be shaped by carpets of microbes on Earth, which can become fossilized in distinctive formations. These microbially-induced sedimentary structures (Miss) formations can be found around the world, in rocks formed over most of the history of the Earth. One example, the Dresser Formation in Western Australia, is estimated to be 3.48 billion years old, possibly the oldest record of life on our planet.
"In one image, I saw something that looked very familiar. So I took a closer look, meaning I spent several weeks investigating certain images centimeter by centimeter, drawing sketches, and comparing them to data from terrestrial structures," Nora Noffke, a geobiologist at Old Dominion University in Virginia, said.
Despite the striking similarities found between the formations on Mars and those created by microorganisms on Earth, this study does not provide proof life once existed on Mars. In order to determine if alien life once existed in lakes and seas of Mars, a rock sample would need to be drilled in the sample, and returned to Earth for analysis. There are currently no missions being planned by NASA that could carry out that task.
"The fact that she pointed out these structures is a great contribution to the field. 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," Penelope Boston, a geomicrobiologist with the New Mexico Institute of Mining and Technology, stated in an article in Astrobiology accompanying the study.
Chris McKay, a planetary scientist working at the Ames Research Center, warned that many theories comparing features on other planets to those on Earth are too quick to assume causes are identical. However, McKay did call the research by Noffke "the most carefully done analysis of the sort that I've seen."
Ancient Sedimentary Structures in the <3.7 Ga Gillespie Lake Member, Mars, that Resemble Macroscopic Morphology, Spatial Associations, and Temporal Succession in Terrestrial Microbialities, detailing investigation of the Curiosity finding, is detailed in the journal Astrobiology.
