Opportunity Rover%26apos;s image analysis: Microbialites on Mars?

作者：Bianciardi Giorgio^*; Rizzo Vincenzo; Cantasano Nicola

来源：International Journal of Aeronautical and Space Sciences, 2014, 15(4): 419-433.

DOI：10.5139/IJASS.2014.15.4.419

• Mars Exploration Rovers
• microbialites
• fractal analysis
• life on Mars

The Mars Exploration Rover Opportunity investigated plains at Meridiani Planum, where laminated sedimentary rocks are present. The Opportunity rover%26apos;s Athena morphological investigation showed microstructures organized in intertwined filaments of microspherules: a texture we have also found on samples of terrestrial (biogenic) stromatolites and other microbialites. We performed a quantitative image analysis to compare images (n=45) of microbialites with the images (n=30) photographed by the rover (corresponding, approximately, to 25,000/15,000 microstructures). Contours were extracted and morphometric indexes were obtained: geometric and algorithmic complexities, entropy, tortuosity, minimum and maximum diameters. Terrestrial and Martian textures present a multifractal aspect. Mean values and confidence intervals from the Martian images overlapped perfectly with those from the terrestrial samples. The probability of this occurring by chance is 1/2(8), less than p%26lt;0.004. Terrestrial abiogenic pseudostromatolites showed a simple fractal structure and different morphometric values from those of the terrestrial biogenic stromatolite images or Martian images with a less ordered texture (p%26lt;0.001). Our work shows the presumptive evidence of microbialites in the Martian outcroppings: i.e., the presence of unicellular life on the ancient Mars.

• 出版日期2014-12