Beyond the GMK cutoff (IMAGE) University of Utah Caption Artist’s illustration of ultra-high-energy cosmic ray astronomy to clarify extremely energetic phenomena in contrast to a weaker cosmic ray that is impacted by electromagnetic fields. Credit Osaka Metropolitan University/Kyoto University/Ryuunosuke Takeshige Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. Adaptations must be shared under the same terms. License CC BY-NC-SA Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.