At www.physorg.com/print190976193.html April 20th … a series of detectors to capture cosmic rays striking the Earth has been set up in Antarctica with the idea of finding neutrino generated signals bounced off the bottom of the ice cap. It is hoped they will be able to pinpoint the unidentified source of ultra high energy cosmic rays. The Earth is constantly peppered by showers of debris from cosmic ray outburst colliding with atoms in the atmosphere. Cosmic rays aren’t actually rays but particles, 90 per cent protons, the nuclei of hydrogen atoms. The other 10 per cent are largely heavy nuclei such as iron. Being electrically charged even the most energetic cosmic rays are forced to bend when they encounter interstellar magnetic fields – and there are a lot of them out there. It is not possible to see where they come from by looking backwards along a straight line trajectory.