All signs point to a supernova. A stellar explosion 2 million years ago that flooded our neighbourhood with charged particles could be the answer to several cosmic puzzles.
For years, astrophysicists have struggled to explain why there are so many high-energy cosmic rays – speeding charged particles that hit Earth from all directions. We’d expect most to have fled the galaxy long before reaching us, yet we see a lot of protons, as well as the antiprotons and positrons they produce in collisions.
Researchers have previously proposed pulsars and dark matter to explain this oddity, but neither provides a complete solution: pulsars can’t explain the antiprotons, and dark matter can’t explain the antiprotons or positrons.
To read more, click here.