  Upward and horizontal tau Air-showers emerging from the Earth crust or
mountain chains are the most powerful signals of Ultra High Energy UHE
neutrinos nu_{tau}, bar\nu_{tau} and bar{nu}_e at PeVs and higher energy. The
multiplicity in tau Air-showers secondary particles,
N_{opt}=10^{12}(E_{tau}/PeV), N_{gamma}= 10^8*E_{tau}/PeV, N_{e^- e^+}= 2*10^7
E_{tau}/PeV, N_{mu}= 3 *10^5 (E_{tau}/PeV)^{0.85} make easy their discover. UHE
nu_tau,bar\nu_tau, following Super Kamiokande evidence of neutrino flavor
mixing, nu_mu<-->nu_tau, should be as abundant as nu_mu, bar\nu_mu.
  Also anti-neutrino electrons, bar\nu_e, near the Glashow W resonance energy
peak, E_{bar\nu_e} = M^2_W / 2m_e = 6.3*10^{15} eV may generate tau
Air-showers.
  Upward UHE nu_tau- N interaction on Earth crust at horizontal edge and from
below, their consequent upward UHE tau air-showers beaming toward high
mountains, air-planes, ballons and satellites should flash gamma, mu, X and
Cherenkov lights toward detectors.
  Such upward tau air-shower may already hit nearby satellite GRO gamma
detectors flashing them by short, hard, diluted gamma-burst at the edge of
BATSE threshold.
  The tau air-shower may test the UHE neutrino interactions leading to
additional fine-tuned test of New TeV Physics both in Mountain Valleys and in
Upward showers.
