The graph on the cover summarizes the nature of the explorations, especially as they relate to the production of various elements in stars. The range of atomic nuclei is graphed with the number of protons along the vertical axis and the number of neutrons along the horizontal.
Black squares indicate stable nuclei of the familiar elements of which Earth is made.
The RIA will explore the uncharted regions beyond this valley and will answer many fundamental scientific questions. The yellow region indicates unstable nuclei that have been produced in the laboratory, only to decay back into stable nuclei after a period of time. Information about these unstable nuclei is very limited, and the RIA is needed to explore their properties more fully. Green areas indicate the many thousands of nuclei whose existence is postulated from theory but is not yet confirmed experimentally. These images show the remnants of dramatic explosions in the cosmos, in which nuclear reactions form the heavy elements in our world.