Violation of the Greisen-Zatsepin-Kuzmin (GZK) Cut-off @ 6x1019 eV.
150 million light-years takes us only to the boundaries of our Local Super-cluster of galaxies (the visible horizon is ~20 billion light-years away). The 3.2x1020 eV cosmic ray could not have come far…
BUT: the arrival direction does not point to any known object.
Possibly new Physics at work!
New exotic particle being observed,
Violation of Special Relativity at UHE energies (Coleman & Glashow, 1998)