Context: ONE light-year is 5.88 trillion miles / 9.46 trillion km
As with lots of the wild-looking things happening in space, these bubbles might be a potential source of the high-energy particles called cosmic rays that strike Earth from outer space. They might even be a source of those cosmic rays whose energies are too high to be accelerated by a single supernova, according to the paper published in the The Astrophysical Journal. The energies and locations of the x-rays demonstrate that the particle acceleration occurred at the outer rim of the bubble, rather than at the center of the galaxy.