  High Energy Neutrino Astronomy energy windows may be ruled by a new Upward
and Horizontal Tau Air-Showers (UpTaus, HorTaus) detectors (scintillators and
optical arrays) located a few kilometers beyond facing High Mountains Chains,
or located above their top or flying on Planes, on Balloons and on Satellites
facing downward to the Earth Crust Horizon. While looking downward to the Earth
seeking for Upward and Horizontal Tau Air-Showers the same optical detectors
may often capture cosmic rays Cherenkov lights reflected or diffused by
downward Shower cosmic rays hitting the Earth soil (a sea,a lake, ice lands,
desert or ground). These new detectors may be built up as a circular hybrid
crown array at high quota facing to horizon in correlation with present largest
telescopes, like Magic or Shalon or ASHRA ones, if able to look below the Earth
edge. The UpTaus and HorTau Astronomy at 10^15 eV up to 10^19 eV energy windows
may test the largest primary neutrino fluxes in Z-Burst neutrino model needed
to solve the GZK puzzle or even the smaller but inevitable GZK neutrino flux
secondary of the same GZK cut-off. These HorTus signals might well be observed
in future EUSO experiment.
