A Nearby OB Association (IMAGE) Washington University in St. Louis Caption Vast bubble in the Large Magellanic Cloud, a satellite galaxy to the Milky Way visible from the Southern Hemisphere, was formed by the explosive death of one or more of the cluster of massive stars inside the bubble. Cosmic rays reaching Earth are created and accelerated by similar explosions. Credit Gemini South Telescope in Chile. Composite by Travis Rector of the University of Alaska Anchorage Usage Restrictions None License Licensed content 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.