What flings mysteriously powerful particles called 'cosmic rays' at Earth? - Space

What flings mysteriously powerful particles called 'cosmic rays' at Earth? Space After 100 years, scientists finally uncover hidden rule behind cosmic rays ScienceDaily Some high-energy particles may turn out to be heavy atoms Universe Space Tech What are some of the highest-energy particles in the universe made of? Scientists have an answer starlust.org Ultrahigh-energy cosmic messengers may carry ultraheavy secrets EurekAlert!