Analysis of Dark Albedo features on a southern polar dune field of mars

András Horváth, Ákos Kereszturi, Szaniszló Bérczi, András Sik, Tamás Pócs, Tibor Gánti, Eörs Szathmáry

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We observed 20-200 m sized low-albedo seepage-like streaks and their annual change on defrosting polar dunes in the southern hemisphere of Mars, based on the Mars Orbiter Camera (MOC), High Resolution Stereo Camera (HRSC), and High Resolution Imaging Science Experiment (HiRISE) images. The structures originate from dark spots and can be described as elongated or flowlike and, at places, branching streaks. They frequently have another spotlike structure at their end. Their overall appearance and the correlation between their morphometric parameters suggest that some material is transported downward from the spots and accumulates at the bottom of the dune's slopes. Here, we present possible scenarios for the origin of such streaks, including dry avalanche, liquid CO2, liquid H2O, and gas-phase CO2. Based on their morphology and the currently known surface conditions of Mars, no model interprets the streaks satisfactorily. The best interpretation of only the morphology and morphometric characteristics is only given by the model that implies some liquid water. The latest HiRISE images are also promising and suggest liquid flow. We suggest, with better knowledge of sub-ice temperatures that result from extended polar solar insolation and the heat insulator capacity of water vapor and water ice, future models and measurements may show that ephemeral water could appear and flow under the surface ice layer on the dunes today.

Original languageEnglish
Pages (from-to)90-103
Number of pages14
JournalAstrobiology
Volume9
Issue number1
DOIs
Publication statusPublished - Mar 31 2009

Keywords

  • Dark Dune Spots (DDS)
  • Mars
  • Seepage
  • Slope streaks
  • Water

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Space and Planetary Science

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    Horváth, A., Kereszturi, Á., Bérczi, S., Sik, A., Pócs, T., Gánti, T., & Szathmáry, E. (2009). Analysis of Dark Albedo features on a southern polar dune field of mars. Astrobiology, 9(1), 90-103. https://doi.org/10.1089/ast.2007.0212