  We point out the opportunity of tau neutrino astronomy for neutrino energies
of the order of 10 GeV to 10$^{3}$ GeV. In this energy range, it is
demonstrated that the flavor dependence in the background atmospheric neutrino
flux leads to drastically different prospects between the observation of
astrophysical muon neutrinos and that of astrophysical tau neutrinos. Taking
the galactic-plane neutrino flux as a targeted astrophysical source, we found
that the galactic-plane tau neutrino flux dominates over the atmospheric tau
neutrino flux for neutrino energies beyond 10 GeV. Hence the galactic-plane can
in principle be seen through tau neutrinos with energies greater than 10 GeV.
In a sharp contrast, the galactic-plane muon neutrino flux is overwhelmed by
its atmospheric background until the energy of $10^{6}$ GeV.
