Potentially habitable flow-like features from Martian dry ice geyser dune spots: Difference between revisions

[[File:Flow-like-features detail.gif|thumb|Flow-like-features detail|Flow-like features on Dunes in Richardson Crater, Mars [http://www.google.co.uk/mars/#q=Richardson%20crater&zoom=2 (Richardson crater in Google Mars)]. They form around the dark dune spots, in the debris of the hypothesized [[Martian Geysers]]. The dark material at the end of the flows moves at between 0.1 and 1.4 m/day in late spring / summer on Mars. This example moves approximately 39 meters in 26 days between the last two frames.<br><br>The two main models involve liquid water - either interfacial layers, or else layers of water created through the solid state greenhouse effect. <ref name="MartínezRenno2013">{{cite journal|url=https://link.springer.com/article/10.1007%2Fs11214-012-9956-3/fulltext.html|last1=Martínez|first1=G. M.|last2=Renno|first2=N. O.|title=Water and Brines on Mars: Current Evidence and Implications for MSL|journal=Space Science Reviews|volume=175|issue=1-4|year=2013|pages=29–51|issn=0038-6308|doi=10.1007/s11214-012-9956-3}}</ref><ref name=Kereszturi2008>Kereszturi, A., et al. [http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1555.pdf "Analysis of possible interfacial water driven seepages on Mars"], Lunar and Planetary Science Conference. Vol. 39. 2008.</ref><ref name="MartínezRenno2013">{{cite journal|url=https://link.springer.com/article/10.1007%2Fs11214-012-9956-3/fulltext.html|last1=Martínez|first1=G. M.|last2=Renno|first2=N. O.|title=Water and Brines on Mars: Current Evidence and Implications for MSL|journal=Space Science Reviews|volume=175|issue=1-4|year=2013|pages=29–51|issn=0038-6308|doi=10.1007/s11214-012-9956-3}}</ref><br><br>Animation centered on {{coord|72.02|S|179.408|E|globe:Mars}} [http://www.google.co.uk/mars/#lat=-72.02&lon=179.408&zoom=7 (location in Google Mars)]. Displayed region 188.5 meters by 172 meters. Dates of sequence: 19 January (sol 396), 24 January (sol 401), 29 January (sol 406), 10 February (sol 418), and 09 March (sol 444), all in 2009. All taken between 4.10 pm and 4.28 pm in Mars local time.]]

 

 

These are probably dry ice effects. Subsurface layers of dry ice are heated by the sun through the solid state greenhouse effect, and erupt as CO2 gas. The dark streaks and spots are thought to be debris from the geysers.

[[Image:DDS MSO.jpg|thumb|right|200px|DDS-MSO hypothesis.]]

In 2003 a team of Hungarian scientists proposed that the dark dune spots and channels may be colonies of [[photosynthesis|photosynthetic]] Martian microorganisms, which over-winter beneath the ice cap, and as the [[sunlight]] returns to the pole during early spring, light penetrates the ice, the microorganisms photosynthesise and heat their immediate surroundings. A pocket of liquid water, which would normally evaporate instantly in the thin Martian atmosphere, is trapped around them by the overlying ice. As this ice layer thins, the microorganisms show through grey. When it has completely melted, they rapidly desiccate and turn black surrounded by a grey aureole.<ref name=Andras >{{cite journal|title=Probable Evidences of Recent Biological Activity on Mars: Appearance and Growing of Dark Dune Spots in the South Polar Region|journal=32nd Annual Lunar and Planetary Science Conference, Houston, Texas, abstract no.1543|date=12–16 March 2001|first=Tibor|last=Gánti |author2=András Horváth |author3=Szaniszló Bérczi |author4=Albert Gesztesi |author5=Eörs Szathmáry|url=http://www.lpi.usra.edu/meetings/lpsc2001/pdf/1543.pdf|format=PDF|accessdate=20 November 2008}}</ref><ref>{{Cite book| author=Pócs, T. |author2=A. Horváth |author3=T. Gánti |author4=Sz. Bérczi |author5=E. Szathmáry |title=ESA SP-545 - Possible crypto-biotic-crust on Mars?| publisher=European Space Agency| date=2003| url=http://adsabs.harvard.edu/full/2004esasp.545..265p| format=PDF| accessdate=24 November 2008 }}</ref><ref>{{cite journal|title=Dark Dune Spots: Possible Biomarkers on Mars?|journal=Origins of Life and Evolution of Biospheres|date=31 October 2003 |first=Tibor|last=Gánti|author2=András Horváth |author3=Szaniszló Bérczi |author4=Albert Gesztesi |author5=Eörs Szathmáry |volume= 33|issue=s 4–5|pages=515–557|doi=10.1023/A:1025705828948|url=http://www.springerlink.com/content/ut8r78131173254n/|accessdate=18 November 2008 }}</ref><ref>{{Cite journal|author=Pócs, T. |author2=A. Horváth |author3=T. Gánti |author4=S. Bérczi |author5=E. Szathmáry |title=38th Vernadsky-Brown Microsymposium on Comparative Planetology - Are the dark dune spots remnants of the crypto-biotic-crust of Mars? |place=Moscow, Russia |date=27–29 October 2003 |url=http://www.colbud.hu/esa/publications/26MosCBC10color.pdf |format=[[PDF]] |accessdate=7 September 2009 |deadurl=yes |archiveurl=https://web.archive.org/web/20110721104952/http://www.colbud.hu/esa/publications/26MosCBC10color.pdf |archivedate=21 July 2011 |df=dmy }}</ref> The Hungarian scientists suggested that that even a complex sublimation process was insufficient to explain the formation and evolution of the dark dune spots in space and time.<ref name=Planetary >{{Cite journal |title=Lunar and Planetary Science XXXIII - Morphological Analysis of the Dark Dune Spots on Mars: New Aspects in Biological Interpretation| editors=A. Horváth, T. Gánti, Sz. Bérczi, A. Gesztesi, E. Szathmáry| date=2002| url=http://www.lpi.usra.edu/meetings/lpsc2002/pdf/1108.pdf| format=PDF| accessdate=24 November 2008 }}</ref><ref>{{cite web|url=http://www.monochrom.at/dark-dune-spots/ |title=Dark Dune Spots – Could it be that it’s alive? |accessdate=4 September 2009 |author=András Sik |author2=Ákos Kereszturi |publisher=Monochrom }} (Audio interview, MP3 6 min.)</ref>

Science fiction writer [[Arthur C. Clarke]] promoted these formations as deserving of study from an [[astrobiology|astrobiological]] perspective.<ref name=Orme>{{cite journal|title=Marsbugs |journal=The Electronic Astrobiology Newsletter |date=9 June 2003 |first=Greg M. |last=Orme |author2=Peter K. Ness |volume=10 |issue=23 |page=5 |url=http://www.lyon.edu/projects/marsbugs/2003/20030609.pdf |accessdate=6 September 2009 |deadurl=yes |archiveurl=https://web.archive.org/web/20090327135109/http://www.lyon.edu/projects/marsbugs/2003/20030609.pdf |archivedate=27 March 2009 }}</ref><ref name=ClarkeSmithsonian2001><ref name=Foulke2001>[[File:BanyanTreesMarsGallery.jpg.638x0 q80 crop-smart.jpg|thumb|The original lower resolution images that looked like banyan trees to Arthur C. Clarke]]