Skip to main content

View Diary: eSci: Incredible Movie of Likely Flowing Water on Mars (100 comments)

Comment Preferences

  •  Thinking on it, can they do some form of spectral (4+ / 0-)
    Recommended by:
    cskendrick, Little, Miggles, Larsstephens

    analysis in lieu of an actual rover?

    •  spectral analysis (1+ / 0-)
      Recommended by:
      Pescadero Bill

      Spectral analysis is either absorption or emission.

      Absorption is much more sensitive, because you're detecting ground-state molecules that can make transitions to excited states.  UV-vis, IR, and microwave are all absorption spectroscopy, and can tell you a lot about the structure of molecules present.  But you have to be able to pass a beam through the sample and detect it on the other side to measure absorption.

      Emission spectroscopy requires some molecules of the sample to be in an excited state already, so you can detect the transitions as they drop to lower energy states and emit photons.  This works for high-temperature systems e.g. stars or gasses with currents passed through them.  The fraction of molecules that are in an excited state, thus capable of making a downward transition, ranges from small to negligible at low temperatures.  I think I've heard that you can do emission spectroscopy of planetary atmospheres, at least in theory, though the practical challenges of collecting enough light from terrestrial scale objects that are light years away (other solar systems) haven't yet been overcome.

      Bottom line, I don't think you could do useful spectroscopy from orbit around Mars.  If you had a rover with built-in spectroscopic (absorption) instruments, that would be better.  But still, organic compounds have to be isolated and purified before spectroscopic analysis will prove much more than "Oh look, carbon-oxygen double bonds!"  That could be something as non-biological as formaldehyde.  (You might do better with high-field nmr, if you could build a liquid-helium-cooled superconducting magnet system with robotic sample preparation, and get it all to work on a remote-controlled robotic rover; definitely nontrivial).

      If we could just give rich people even more money, then everyone would be better off.

      by lilnev on Thu Aug 04, 2011 at 07:14:00 PM PDT

      [ Parent ]

Subscribe or Donate to support Daily Kos.

Click here for the mobile view of the site