  We point out the opportunity of the tau neutrino astronomy for the neutrino
energy E ranging between 10 GeV and 10^3 GeV. In this energy range, the
intrinsic tau neutrino production is suppressed relative to the intrinsic muon
neutrino production. Any sizable tau neutrino flux may thus arise because of
the \nu_{\mu}\to \nu_{\tau} neutrino oscillations only. It is demonstrated
that, in the presence of the neutrino oscillations, consideration of the
neutrino flavor dependence in the background atmospheric neutrino flux leads to
the drastically different prospects between the observation of the
astrophysical muon neutrinos and that of the astrophysical tau neutrinos.
  Taking the galactic-plane neutrino flux as the targeted astrophysical source,
we have found that the galactic-plane tau neutrino flux dominates over the
atmospheric tau neutrino flux for E > 10 GeV. Hence, the galactic-plane can at
least in principle be seen through the tau neutrinos with energies just greater
than 10 GeV. In a sharp contrast, the galactic-plane muon neutrino flux is
overwhelmed by its atmospheric background until E > 10^6 GeV.
