HOW to find underground frozen water on Mars - Without NASA rover drills

-A thin atmosphere misgivings in optical height variances is surely compensated by huge diurnal temperature variations.

   The long time quest for water on Mars has been resolved for some time,  there is some,   but it may be easier to find huge permafrost lakes by simply looking at the horizon line.  Mars Permafrost,  should be similar to Arctic permafrost,  just as much as Arctic sea ice.  Permafrost leaves a drier interface than water,  but unlike water,  ice is an insulator,  like permafrost.  In the Martian under shallow rock  permafrost,  the ground temperature  should be kept colder than with thick dry rock layers. 

       Rapid conduction sun forced diurnal atmospheric inversions are a feature found with sea ice,  permafrost does the same.  Martian atmosphere is 100 times thinner than on Earth,  however there is one.  Where there is an atmosphere there is atmospheric refraction.  One must observe there more carefully.

    To prove this,  one of the rovers must take pictures  at 3 hours intervals after Local Apparent Midnight and Noon,  without moving at all.  The same pictures will show a different horizon line something like:

   A weak evening inversion happens when the sun lowers over a clear High Arctic horizon of sea ice.     Ice has a heat capacity more than twice as strong as Earth air,  heat capacity of Mars atmosphere is weaker.   However,  heat capacity of rocks ,  either on Earth or Mars is lesser than ice.  For these reasons,  if there is any ice under a relatively shallow layer of rocks,  the horizon line should vary compared to dry rock sub-surface,   with a variance lesser than on Polar Earth,  but vary nevertheless.  We should find water there by analyzing horizon permutations especially with very good  photographic equipment.  WD April 25,2014


   Ice warms or cools much slower than the Martian atmosphere,  in a given substratum,  a pure rock formation would vary horizon heights more significantly than one with permafrost.  The way to detect a variation  without multiple pictures taken from the same position would be to study wide horizon pictures which would bring out a profile look of an apparent "lake without water",  the middle of this " empty lake" would appear deeper than "shorelines".    The dry rock stratum would appear higher because rocks warm faster than ice. 

     The Mars curiosity rover has at least one such NASA picture :

   This is the kind of single picture needed to detect permafrost on Mars. There is an apparent horizon sun line,  a bright line just above the horizon, it is an optical feature from an atmospheric structure suggesting that indeed, the horizon is flat,  this bright line also implies great refraction.  The middle of the picture shows a very small drop in horizon from the right,  more prominent from the left.  Permafrost,  frozen water mixed with Mars dirt,  may be under horizon land in the middle of this picture .  This requires a verification of how flat this horizon is,  by taking multiple pictures from the same spot and from other means...   WD October 30 2017