An article in Science, Evidence for High-Energy Extraterrestrial Neutrinos at the IceCube Detector, claims to have detected 28 neutrinos from an unidentified extra-solar location that has yet to be identified. From what I can gather, the only evidence for determining the origin of a neutrino is based only on the energy of said neutrino. Based on the large energy content of those observed, the hypothesis is that the neutrinos are from outside the solar system, making them the first extra-solar neutrinos ever detected.
How accurate is using energy to identify the neutrinos? Presumably it is statistically possible, although perhaps very unlikely, that the energies observed were created inside the solar system. Is there a probability density function describing expected energy values for atmospheric and intra-solar-system generated neutrinos? Where do the newly observed neutrinos fit into those probabilities?