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Curiosity Rover Collects First Martian Bedrock Sample

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  • by oodaloop (1229816) on Saturday February 09, 2013 @03:28PM (#42845017)
    I've been clicking on TFS, but no webpage comes up. Is there a link somewhere?
  • Article (Score:5, Informative)

    by skelly33 (891182) on Saturday February 09, 2013 @03:36PM (#42845081)
    Link [nasa.gov]
  • by SternisheFan (2529412) on Saturday February 09, 2013 @03:48PM (#42845173)
  • Re:Erosion (Score:5, Informative)

    by sensei moreh (868829) on Saturday February 09, 2013 @04:22PM (#42845393)
    Erosion exposes a new surface to weathering, and a weathered surface can have a chemical composition significantly different than the unweathered interior.
  • Re:Erosion (Score:4, Informative)

    by kipsate (314423) on Saturday February 09, 2013 @04:36PM (#42845507)
    Wind, temperature changes and radiation from the sun pretty much define the weather on Mars. Any changes to the chemical composition on the rock surface will be due to these factors. Therefore don't expect anything exciting.
  • Re:Erosion (Score:4, Informative)

    by Ford Prefect (8777) on Saturday February 09, 2013 @08:49PM (#42847067) Homepage

    Granted the top layer, which is all we have studied up until now will be nothing exciting (likely layers of dust deposited over millennia), but unexposed layers have a lot of historic potential.

    The stuff they're looking at is rock that's (very) slowly being further exposed through erosion by the wind - the rocks formed early in the history of Mars, then newer, upper layers have eroded away, exposing this particularly old stuff dating from around the time life began on Earth. If Mars had similar conditions, then it's a good place to look for remnants of organic molecules...

    The aim of the drill is to get to rock that's not been significantly irradiated by cosmic rays. From this paper on The Sample Analysis at Mars Investigation and Instrument Suite [springer.com]:

    Ancient indigenous organic molecules could be also destroyed or transformed by the ionizing radiation in the shallow subsurface of Mars. Due to a thin martian atmosphere and lack of magnetic field, the surface of Mars has been bombarded continuously by the energetic particles of the galactic and solar cosmic rays (GCRs and SCRs) for much of its history. Unlike UV radiation which is absorbed in the first mm of soil (Mancinelli and Klovstad 2000; Cockell et al. 2005), GCRs can penetrate down to 1 meter below the surface (Dartnell et al. 2007). Over the long period of exposure, cosmic rays particles have the capacity to transform complex organic compounds into macromolecules having different, more refractory chemistry and/or into smaller molecules broken from a parent molecule. The latter case may occur either by direct impacts or by secondary reaction with oxidative radicals produced by radiation in the immediate vicinity of the organic molecules (Dartnell et al. 2008). It is not clear how such long-term degradation would affect SAM’s measurements of organic compounds at the ancient geologic outcrops because the rates of erosion are highly variable on Mars (Golombek et al. 2006). Erosion of the ancient rock would naturally expose “fresh” (less irradiated) material to the surface with potentially “unbroken” organic molecules. Furthermore, SCRs, which are less energetic than GCRs, cannot penetrate and destroy organic matter deeper than 2 cm below the surface (Pavlov 2011). Therefore, MSL’s drilling and sampling of outcrops from 5 cm below the surface will exclude the effects of degradation of organic matter by solar cosmic rays. Finally, using the radiolysis constants of amino acids Kminek and Bada (2006) and Pavlov (2011) demonstrated that simple organic compounds with masses below 100 amu, should have a good chance to survive long-term exposure to GCRs in the shallow subsurface even extremely low surface erosion rates. Results from Curiosity’s Radiation Assessment Detector (RAD) will provide modern radiation characteristics that will help improve long-term modeling of the surface radiation on Mars and possibly constrain its affects on near surface organic chemistry.

  • Re:Erosion (Score:4, Informative)

    by FatLittleMonkey (1341387) on Sunday February 10, 2013 @12:00AM (#42847899)

    However, the surface is covered in cruft, baked in the sun, exposed to the atmosphere. Note the colour difference between the drill-hole and the rest of the surface.

    By drilling down even a little, you are ensuring that you really are seeing raw bedrock. A pure sample, which you can compare with the surface of the same rock, subtract one from the other and be left with just the cruft. Now you can check whether you have been correctly... errr... correcting for cruft in your samples of rocks which are too far out of Curiosities path to reach with anything other than the laser-and-spectrograph.

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