After more than a century of intensive research, we know a lot about cosmic rays. But many mysteries remain. We do know: What they’re made of. About 90% of them are hydrogen, 9% are helium, and 1% are ...
Ultra-high energy cosmic rays are orders of magnitude more powerful than the sun's energetic particles: They can reach up to 10 20 electron volts, whereas particles from the sun can reach up to 10 ...