  The discover of Ultra High Energy Neutrino of astrophysical nature may be
already reached. Indeed upward and horizontal tau Air-showers emerging from the
Earth crust or mountain chains offer the best and most powerful signal of Ultra
High Energy UHE neutrinos nu_tau}, bar\nu_tau and bar{\nu}_e at PeV 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 its over-amplified
discover. Indeed UHE nu_tau, following Super Kamiokande evidence of neutrino
flavour mixing, should be as abundant as nu_mu. Also anti-neutrino electrons,
bar{\nu}_e, near the Glashow W resonance peak, E_{\bar{\nu_e}} = M^2_W / 2m_e,
may generate tau Air-showers. Such horizontal tau air-showers by nu_{\tau}-N
and UHE bar\nu_{e}-e at PeVs emerging from mountain high chain is one of the
most power-full UHE neutrino imprint. Upward UHE nu_{\tau}- N interaction on
Earth crust at horizontal edge and from below, their consequent UHE tau
air-showers beaming toward high mountains should flash gamma,mu,X and Cherenkov
lights toward detectors located on the top of the mountains or on balloons.
Such upward tau air-shower may hit also nearby satellite flashing them by
short, hard, diluted gamma-burst at the edge of most sensitive Gamma Ray
Observatory BATSE threshold. We identify already these rarest gamma events with
recent (1994) discovered upward Terrestrial Gamma Flashes (TGF); we show their
very probable UHE tau-UHE \nu_\tau origin. Partial TGF Galactic signature and
known galactic and extra-galactic source location are discovered within known
47 TGF events at low, 2 10^{-3}, probability threshold.
