Well, that's how many 9s are used in the article before us. That's how close to the speed of light ("c") that the so-called "high-energy cosmic rays" are travelling when they smash into the earth's upper atmosphere. More impressive is the fact that these speedy microscopic subatomic particles pack a macroscopic wallop. Would you believe a proton with the energy of a 120-mileper-hour fast ball?
These super cosmic rays are so energetic that our galaxy's magnetic field hardly influences their trajectories at all. Astronomers really cannot tell where they come from. Even more disconcerting, the energies of these cosmic cannonballs surpass by many orders of magnitude anything terrestrial scientists can crank up in their most powerful atom smashers. Somewhere out there, perhaps between in the vast voids between the galaxies, lurks the mother of all particle accelerators.
(Semenluk, Ivan; "Showered in Mystery," Astronomy, 29:43, January 2001.)
Comment. Of course, those cosmic voids are not really empty! See next item.