SOMETHING fairly close seems to be hurling energetic, charged particles at Earth. But what?
The IceCube neutrino observatory at the South Pole detects muons created when the charged particles known as cosmic rays hit Earth’s atmosphere, and their direction of travel. Now a map of these cosmic rays, drawn up by Stefan Westerhoff and colleagues, has revealed a southern sky with cosmic ray “hotspots”, rather than an even distribution of particles.
These hotspots must originate within 300 billion kilometres of Earth: further out, magnetic fields should deflect the particles so much that hotspots would be smeared out across the sky.…
