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astrophysical uhe neutrinos is being searched , since four decades , at tev - pev energy via neutrino muons in underground detectors . their signal is greatly polluted from above ( and below ) by cr secondary muons ( and atmospheric muon neutrinos into muons ) and partially suppressed at pevs , by earth size opacity . horizontal muons at hundreds tev , originated by astrophysical uhe neutrinos are also polluted by leading prompt atmospheric signals . however , since four decades , the rise of highest energy neutrino astronomy is generally expected also by the cosmogenic eev neutrinos , secondaries of gzk @xcite,@xcite cut - off on ultra high cosmic rays ( uhecr ) . these ones are difficult to observe in @xmath5 detector . but since a decade @xcite the uhe tau neutrino astronomy have been foreseen and suggested in present and future detectors . indeed tau air - shower astronomy is an amplified neutrino astronomy observable . indeed an air - shower is not a single track , but a wide ( even many @xmath6 ) area raining of billions secondaries at once . one does nt need to collect and count all of them to realize such an event beyond a mountain or earth screen . one need just a spread sample at once . as for uhecr . moreover hadronic air - shower below zenith angle @xmath7 are originated far and far and they are filtered : their peak electromagnetic component is exhausted at horizons leaving just late diluted ( and sharp ) inclined muon bundles . on the contrary neutrino , either interacting in air or , better , escaping the earth by @xmath8 may lead to electromagnetic - rich horizontal ( upward ) air - showers . tau decay in flight are better than neutrino interacting in air because earth rock density is three thousand times larger than air one . even if the tau enjoy of a bounded escaping solid angle ( a zenith angle width of @xmath9 degree ) while all down - ward neutrinos interacting on air may reach from wider cone ( a zenith angle width @xmath10 degree ) and are in three flavors . such skimming events in auger experiment may rise via upward tau air - shower @xcite,@xcite,@xcite . in last years the upward - horizontal eev @xmath11,@xmath12 appearance , via uhecr @xmath13 has been predicted by many authors ; the most extreme ones were at rate of @xmath14 a year@xcite , or @xmath15 a year in auger @xcite and finally up to @xmath16 a year @xcite . this rate , has only recently being adjusted and confirmed by last auger group estimates ( now 2008 , cris 2008):@xmath15 a year , in full agreement with our previous ones @xcite . indeed following the auger evidences ( and hires ones @xcite ) of an uhecr gzk@xcite,@xcite cut - off and the latest auger ( possible ) super - galactic anisotropy due to an eventual proton uhecr guarantee a secondary flux of uhe - gzk neutrino at eevs energy within auger detection via @xmath11,@xmath12 showering @xcite . in fact this occurs because the muon neutrino flavor mixing must feed also a tau neutrino component . such uhe astrophysical tau neutrino ( noise - free from any atmospheric background ) may interact in and it may rises out the earth as uhe @xmath11 . the uhe @xmath11,@xmath12 decay in flight in atmosphere must lead to loud tau air - showers . such a detectable flashes may rise in short times within auger sd ( by large electromagnetic curvature signals ) or in fd arrays by horizontal fluorescence signals , namely once in a few years ( @xmath17 ) from now @xcite . nevertheless a recent alternative uhecr understanding @xcite , based on observed auger uhecr ( nuclei ) mass composition and with cen - a rich clustering map , is in disagreement with uhecr proton understanding @xcite . this model is leading to different uhe neutrino predictions . it suggests that uhecr are made by lightest nuclei ( @xmath0 , @xmath1 , maybe a few also @xmath18,@xmath19 ) mostly originated from cen - a : their trajectories are bent and spread by galactic magnetic fields and they are incidentally clustered ( by galactic fields ) around cen - a , nearest ( @xmath20 mpc ) and possibly unique source able to survive the short lightest nuclei gzk cut - off . these events spread mostly along the same super - galactic arm , just apparently from far @xmath21 mpc centaurs cluster . the mean random angle bending @xmath0 ( see fig.[uhecr - map ] ) by spiral galactic magnetic fields along the plane is @xmath22 : @xmath23    , li , be ) will be bent more . the lighter and less energetic @xmath24 less . , width=226 ]    this _ lightest nuclei for highest cosmic rays _ model implies and foresees among the other , additional clustering of uhecr events around the nearest agn cen - a ( the lightest uhecr the more correlated to the source , the heavier and with larger charges , the most bent and spread ones ) . the model explains the absence or a poor signal from virgo ( too far for the fragile nuclei to fly by ) . lightest nuclei for highest cosmic rays _ are forced in a very confined cosmic volume ( ten mpc ) due to a fragile light nuclear ( few mevs ) binding energy . usually heavy nuclei fragmentation pour energy only in uhe neutrino ( at @xmath25 eev energy ) spectra , less energetic than common uhe eev @xmath26 neutrino flux . auger sd or fd are not able to reveal tens - hundreds pev energy easily . however a very recent and a less spaced auger sub - system , a more dense array amiga and the additional telescopes heats might lower the threshold accordingly . the @xmath28 mostly hadronic , inclined-_upward _ , tau air - showers @xmath29 occur at much lower altitudes than hadronic inclined _ down_-going air - showers , at much nearer distances from telescopes than hadronic eev air - showers , reducing the area and the rate . they may offer a tens - hundred pev neutrino windows , secondaries of uhe he nuclear fragmentation . some estimates are offered assuming , for sake of simplicity a fermi - like uhe gzk spectra , comparable to the well known waxmann - bachall flux derived for cosmic grbs . nevertheless if rarest uhecr , possibly from agn , above @xmath30 , ( a few in auger events ) , are also he nuclei , they may still suffer gzk photo - pions opacity decaying into eev neutrinos too . such he gzk interaction may be comparable with corresponding proton gzk ones at @xmath31 : therefore eev tau neutrino astronomy , tails of the most energetic lightest nuclei gzk secondaries , may still rise at auger . eev inclined tau decays , born nearly at sea level ( versus inclined hadronic @xmath32 ones developing at altitudes well above ten km ) occur at air - density at least three times higher ( than hadron horizontal ones ) ; therefore tau air - showers ( mostly behaving as hadron ones ) , their electromagnetic and fluorescence tail sizes ( and times ) are three times shorter ( @xmath33 km ) and their characteristic azimuth speed @xmath34 is slower than common inclined uhecr hadron ones at higher altitudes ( @xmath35 km ) , ( @xmath36 km ) , whose detection threshold ( minimal impact distance ) is very near to the observer ( a dozen of km from the edges and few kms from air - shower baricenter ) . the consequent azimuth angular velocity is for instance , assuming an eev event , at maximal distance of @xmath37 km , at minimal distance @xmath38 km , total duration 100 @xmath39 s , @xmath40 . such a brief @xmath41s and distinct up - ward tau lightening versus slow @xmath42s diluted down - ward horizontal showering may be well disentangled within auger ( and amiga sd ) threshold , also by obvious angular resolution and directionality ( up or downward ) ; their strong curvature and their inclinations would rise within heat fd and auger fd , we estimate , once every a couple of years [ array ] . possibly ( factor two ) originated from the ande side ( west to east ) @xcite,@xcite,@xcite .     and the 23.5 @xmath6 ) offer a lower energy threshold for neutrino inclined air - showers respectively at @xmath43 and @xmath44 ev . in the figure a schematic area due to air - showering lobes of an escaping horizontal air - shower , width=226 ]    this new neutrino astronomy , the pevs - eevs ratio , may disentangle in future records the real uhecr nucleon or lightest nuclei uhecr nature . indeed the additional rise of the resonant glashow contribute , @xmath45 , in the upgoing tau , while just marginally doubling the signal at 0.01 eev , see fig.[nulenght],[differential],[integral ] it may leave a clear imprint on horizontal differential angular spectra . leading to a flavor uhe neutrino spectroscopy .      the role of uhe neutrino interaction with matter is well understood : they also shape the neutrino survival across the earth . indeed the highest energy @xmath4 are opaque to earth , but not to smallest cord . therefore the harder events are the more opaque and survive at shortest cords , the tangent ones . the resonant @xmath46 are very peculiar signals . their opacity on earth is extreme . they are as opaque as eev energetic neutrinos.see [ nulenght ] . but their lower energy corresponds to higher flux ( for constant energy fluency as waxmann bachall one ) . but their propagation in earth is much smaller too . the compensated flux in 5 - 6 times higher than eev one . unfortunately this rate is ( in auger ) suppressed by detection threshold ( nearly one hundred times smaller than eev showers ) . nevertheless the mini array amiga ( of 6 @xmath6 ) and the heat telescopes may contribute to make detectable in a few year the same resonant @xmath46 : the distance will be ten times smaller and the showering azimuth angular velocity will appear @xmath47 times faster than already fast eev tau airshower . their curvature in amiga may leave a clear imprint in dense array cherenkov ( and in mostly absent underground ( 3 m ) muon one ) . , for each neutrino flavor , derived from the observed uhecr gzk@xcite,@xcite at @xmath48 ev . the inner earth density profile has been taken into account . note the very peculiar bump due to the resonant antineutrino at @xmath49 pev ; its preferential inclination is due to the severe earth opacity . the overall integral signal almost double the tau skimming rate in the same energy band , width=226 ]     , for each neutrino flavor , derived from the observed uhecr gzk@xcite,@xcite at @xmath48 ev . the inner earth density profile has been taken into account . note the very peculiar bump due to the resonant antineutrino at @xmath49 pev ; its preferential inclination is due to the severe earth opacity . the overall integral signal almost double the tau skimming rate in the same energy band , width=272 ]     efficiency for fd . the fd threshold is growing linearly with energy and it is respectively @xmath50 , @xmath51 , @xmath52 at the energy @xmath53 , @xmath28 , @xmath54 eev . because of it each rate at lower energies than eev must be suppressed in fd efficiency by corresponding factor ( 0.1 , 0.01 ) making the expected event rate at ten pev ( @xmath55 ) and hundred pev ( 0.5 ) , just below unity in 3 years . the additional mini - array amiga at @xmath56 , @xmath57 , whose array spacing is respectively , @xmath58 , @xmath59 m. is a sd active day and night and it might double the signal , offering a detection in a few years from now ( 0.35 - 0.4 event / year).,width=302 ] the very exciting neutrino astronomy is beyond the corner . either by eev gzk @xcite,@xcite secondaries or by tens pev signals the detection via fd in auger is at the detection edge . the short and near air - shower from the telescope due to the lower energy makes the shower timing brief , sharp and at small zenith angle , and , upgoing . on the contrary the unique inclined horizontal down - going hadron shower are far away , diluted in air density and in time scale as well as at possible bifurcate ( by geomagnetic field ) structure . no way to be confused . three or more times duration and morphology of _ up or down _ signature will disentangle any rare neutrino lights arriving from their unique but unusual sky : the earth . their rate , timing , energy and inclination may teach us on the real nature ( nucleon or lighters nuclei ) of uhecr . in this hope we suggest ( a ) to implement the present auger array with additional array searching for shadows of inclined hadronic from ande in auger ; ( b ) to add mini - cherenkov telescope arrays facing ande screen to reveal tau air - showers signals beyond the mountain chain also via direct cherenkov flashes.(c ) locating a new telescope array few km distance to reduce the energy thresholds ( d ) introducing novel trigger detection by fast horizontal track time signature.(e ) locating sd nearest to fd in order to enlarge their ability to discover the inclined events ( blazing cherenkov flashes ) both in fd and in cherenkov lights as well as in muon tracks in nearby sd array elements . it must be remind that the amiga muon versus sd cherenkov signal may well signal the electromagnetic versus muonic nature of horizontal air - shower , offering an additional tool to disentangle neutrino versus hadronic air - showers . we foresee in very near years , possibly this and next one , the tau neutrino astronomy birth , if accurate attention on trigger thresholds , and amiga - heats implementation will be concluded soon .
uhecr may be either nucleons @xcite or nuclei ; in the latter case the lightest nuclei , as @xmath0 or @xmath1 , li , be , explains at best the absence of virgo signals and the crowding of events around cen - a bent by galactic magnetic fields @xcite . 
 this model fit the observed nuclear mass composition discovered in auger . 
 however uhecr nucleons above gzk produce eev neutrinos while heavy nuclei , as fe uhecr do not produce much . 
 uhecr he nuclei at few @xmath2 suffer nuclear fragmentation ( producing low energetic neutrino at tens pevs ) but it suffer anyway photo - pion gzk suppression ( leading to eev neutrinos ) once above one - few @xmath3 . 
 both these cosmogenic uhe secondary neutrinos signals may influence usual predicted gzk @xcite,@xcite tau neutrino astronomy @xcite in significant and detectable way ; the role of resonant antineutrino electron - electron leading to tau air - shower may also rise .