A Martian Size Paradox:

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Feb 7, 2017.

  1. paddoboy Valued Senior Member

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    http://www.marsdaily.com/reports/Curiosity_rover_sharpens_paradox_of_ancient_Mars_999.html

    Curiosity rover sharpens paradox of ancient Marsby Staff WritersPasadena CA (JPL) Feb 07, 2017

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    Bedrock at this site added to a puzzle about ancient Mars by indicating that a lake was present, but that little carbon dioxide was in the air to help keep a lake unfrozen. Image courtesy NASA/JPL-Caltech/MSSS. For a larger version of this image please go here.
    Mars scientists are wrestling with a problem. Ample evidence says ancient Mars was sometimes wet, with water flowing and pooling on the planet's surface. Yet, the ancient sun was about one-third less warm and climate modelers struggle to produce scenarios that get the surface of Mars warm enough for keeping water unfrozen.

    A leading theory is to have a thicker carbon-dioxide atmosphere forming a greenhouse-gas blanket, helping to warm the surface of ancient Mars. However, according to a new analysis of data from NASA's Mars rover Curiosity, Mars had far too little carbon dioxide about 3.5 billion years ago to provide enough greenhouse-effect warming to thaw water ice.

    The same Martian bedrock in which Curiosity found sediments from an ancient lake where microbes could have thrived is the source of the evidence adding to the quandary about how such a lake could have existed. Curiosity detected no carbonate minerals in the samples of the bedrock it analyzed. The new analysis concludes that the dearth of carbonates in that bedrock means Mars' atmosphere when the lake existed - about 3.5 billion years ago - could not have held much carbon dioxide.

    The article concludes.....
    "When two lines of scientific evidence appear irreconcilable, the scene may be set for an advance in understanding why they are not".
    http://www.marsdaily.com/reports/Curiosity_rover_sharpens_paradox_of_ancient_Mars_999.html
    Interesting.....
    Perhaps volcanic/eternal heating source?
     
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  3. Michael 345 Valued Senior Member

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    Perhaps left over radiation from the atomic wars?

    And the lake vanished when the radioactivity was low enough the Martians made beer

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  5. paddoboy Valued Senior Member

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    It seems that a similar paradox also applied to Earth......
    https://en.wikipedia.org/wiki/Faint_young_Sun_paradox
    The faint young Sun paradox describes the apparent contradiction between observations of liquid water early in Earth's history and the astrophysical expectation that the Sun's output would be only 70 percent as intense during that epoch as it is during the modern epoch. The issue was raised by astronomers Carl Sagan and George Mullen in 1972.[1] Explanations of this paradox have taken into account greenhouse effects, astrophysical influences, or a combination of the two.

    The unresolved question is how a climate suitable for life was maintained on Earth over the long timescale despite the variable solar output and wide range of terrestrial conditions
    more........................
     
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  7. paddoboy Valued Senior Member

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    The link goes on and suggests as possibilities what I suggested earlier in the piece [volcanic/eternal heating] and also raises another valid point, re the Moon being a lot closer to earth, and subsequently increased tidal gravitational effects.
     
  8. timojin Valued Senior Member

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    Water on Mars Mystery Continues, Carbon Dioxide Too Low, Scientists Say
    http://www.newsmax.com/newsfront/water-on-mars-mystery/2017/02/06/id/772269/

    he early atmosphere on Mars did not have enough carbon dioxide to support liquid water, new research shows – deepening the mystery on how the Red Planet could have been once filled with lakes and oceans.

    New research published in the Proceedings of the National Academy of Sciences goes over data from the rover Curiosity's analysis of 3.5 billion-year-old rocks from Gale Crater, where scientists think an ancient lake was once located, The Wall Street Journal reported.

    The rover's X-ray diffraction instrument, which identifies the minerals present in a rock sample, did not turn up any carbonates; with that evidence and the amount of other minerals present, researchers then figured Mars' atmosphere must have had very little carbon dioxide.

    "What we see is a lot lower than the amount needed to produce the greenhouse effect to have lakes and rivers around at that time," Thomas Bristow, a research scientist at the NASA Ames Research Center in Moffett Field, Calif., and lead author on the paper, told the Journal.

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    An atmosphere with plenty of carbon dioxide would be the simplest answer, Bristow added, but "it doesn't seem that easy solution will work in this case."

    One answer could be brief and repeated warm periods in which water melted, Paul Niles, a planetary scientist at NASA's Johnson Space Center, who was not involved in the research, told the Journal.

    Other gases might also have contributed to warming Mars in the absence of carbon dioxide, Raymond Arvidson, a professor at Washington University in St. Louis and scientist on the Curiosity and Opportunity rover teams, told the Journal.
     
  9. paddoboy Valued Senior Member

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    Thank you timojin, although your article is essentially the same as in the OP.
    And remember the same situation exists with good old Mother earth.....explantions are forthcoming, its just knowing which one is actually correct.
    I'm with the eternal heat of the Earth and tidal gravitational effects by a Moon that was a lot closer to Earth. Do you agree?
    Although the tidal gravitational effects obviously do not apply to Mars as far as we know.
     
  10. Ophiolite Valued Senior Member

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    I am sure the researchers will have considered the lowering of freezing point from dissolved salts. If the ancient Martian lakes were saturated brines they could have remained liquid at significantly lower temperatures. I should like to see what calculations have been made in this regard. I repeat that I am sure it will have been considered - the alternative is too horrible to contemplate.
     
  11. timojin Valued Senior Member

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    I put this purposely long ago You were arguing there is water , I said show me , but you kept pushing your agenda . It is nice perhaps you can change your agenda, stick to the fact, keep bringing your pictures they are nice.
     
  12. paddoboy Valued Senior Member

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    Science is my agenda timojin, and there certainly is water on Mars, 100% frozen on the surface and possibly liquid below, but it is there.
    Perhaps you need to read your articles again.
     
  13. paddoboy Valued Senior Member

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    In fact according to some sources, some liquid water may still at times flow on Mars.....
    http://www.space.com/17048-water-on-mars.html
    October 7, 2015
    Liquid water may still flow on Mars, but that doesn't mean it's easy to spot. The search for water on the Red Planet has taken more than 15 years to turn up definitive signs that liquid flows on the surface today. In the past, however, rivers and oceans may have covered the land. Where did all of the liquid water go? Why? How much of it still remains?
     

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