(12.7.2018) As early as the 1780s, French physicist Charles-Augustin de Coulomb noticed that charged particles were neutralizing the electric charge of some of his experiments. In 1912, Austrian scientist Victor Hess first demonstrated that these particles were arriving from space.
This leads to strong motivations to detect the BZ neutrino flux: first, it is required by standard model physics, and thus its absence could signal new physics beyond the standard model.
(27.9.2018) However, twice, during its first flight 2006 and its third flight in 2014, ANITA detected odd radio waves with unflipped polarizations coming up from the surface below instead of the horizon. That suggests the signals were produced by upward-zooming air showers triggered by particles that tunneled through Earth. At first blush, that’s not a problem for the standard model. Neutrinos barely interact with matter, so a couple of cosmic neutrinos might have barreled through the planet before smacking an atomic nucleus in the ice and setting off an upward air shower.