Most elemental abundances can be accurately predicted by two processes: Stellar nucleosythesis and Big Bang nucleosynthesis. Stars are constantly fusing Hydrogen and Helium into heavier and heavier elements, and are generally responsible for the evolution of chemical abundances in the universe. LiBeB elements, however, are not formed by either one of those processes. Where, then, does LiBeB come from? How is it made?
It is these questions that make LiBeB elemental abundances such a mystery. Research has suggested that cosmic rays play a significant role in LiBeB formation. But before this connection is more thoroughly explored, it is necessary to examine what is known about cosmic rays.
Next Up: An Introduction to Cosmic Rays