Donald Delbert Clayton (born March 18, 1935) is an American astrophysicist whose most visible achievement was prediction on sound nucleosynthesis grounds that supernovae are intensely radioactive. That earned Clayton the NASA Exceptional Scientific Achievement Medal (1992) for “theoretical astrophysics related to the formation of (chemical) elements in the explosions of stars and to the observable products of these explosions”. Supernovae became the most important stellar events in astronomy owing to their profoundly radioactive nature.
Clayton's works surprised astrophysicists with foundational ideas for five original subfields of astrophysical: (1) nucleosynthesis, the assembly of the atomic nuclei of the common chemical elements by nuclear reactions within the stars; (2) astronomy of gamma-ray lines emitted by radioactive atoms created and ejected by supernovae; (3) growth in time of the interstellar abundances of radioactive atoms; (4) predicted existence of interstellar cosmic dust grains, which he named stardust, containing isotopically identifiable condensation of radioactive atoms; (5) predicted condensation of solid grains of carbon within hot, oxygen-dominated radioactive supernova gases. Clayton published these original ideas from research positions at California Institute of Technology, Rice University, Cambridge University, Max-Plank Institute for Nuclear Physics, Durham University and Clemson University during an academic career spanning six decades.
Clayton also authored four books for the public: a novel, The Joshua Factor (1985), is a parable of the origin of mankind utilizing the mystery of solar neutrinos; a science autobiography, Catch a Falling Star; a mid-career memoir The Dark Night Sky, of cultural interest owing to Clayton's conception of it in 1970 as layout for a movie with Italian filmmaker Roberto Rosselini about growing awareness during a cosmological life (See Personal below); Handbook of Isotopes in the Cosmos (Cambridge Univ. Press, 2003), describing in prose the nuclear origin of each isotope of our natural elements and important evidence supporting each nuclear origin. Clayton has published on the web Photo Archive for the History of Nuclear Astrophysics from his personal photographs and his researched captions recording photographic history during his research in nuclear astrophysics.