THE origin of cosmic rays, the high-energy particles that bombard the Earth
from space, has long been a mystery. But now astronomers have evidence that at
least some of these particles are accelerated in the supernova explosions that
occur when a star dies.
Astronomers have known since 1912 that the Earth is being continually
bombarded by highly energetic particles such as protons. Scientists believe that
many cosmic rays must come from supernovae inside our Galaxy but have never had
proof. Because the particles are charged, magnetic fields deflect them as they
travel through the Galaxy, making it impossible to know…
