  The ANITA collaboration has recently announced the supposed observation of
two upward going cosmic ray showers at earth emergence angles $27^{\circ}$ and
$35^{\circ}$ with reconstructed energy $\sim$0.6~EeV. Upward air showers (UAS)
are expected from tau leptons resulting from the interaction of astrophysical
neutrinos inside the Earth. However, at emergence angles larger than
$20^{\circ}$, the probability of tau emergence from a neutrino is less than
$10^{-7}$, which makes a standard model explanation for these signals
difficult.
  If confirmed by other experiments, these energetic events would strengthen
the argument for physics beyond the standard model. Both the proposed EUSO-SPB2
and the POEMMA instruments will be equipped with optical Cherenkov detectors in
order to measure the Cherenkov emission from UAS, which, if aimed low enough
below the horizon, could, in principle, capture these events as well. An
observation in the Cherenkov channel would help to rule out anthropogenic and
other explanations for these events. We present here the sensitivity to the
ANITA anamolous events for a balloon based and a satellite based Cherenkov
detector, as could be realized in the upcoming EUSO-SPB2 mission and the
proposed POEMMA mission, respectively.
