Planetary Nuclear Spectroscopy*

Measurements of gamma-ray and neutron emissions from planetary surfaces - collectively termed planetary nuclear spectroscopy - provide measurements of the elemental composition of near-surface materials. Previous nuclear spectroscopy investigations have enabled numerous discoveries about the formation and evolution of rocky worlds within our solar system, including the Moon, Mars, Mercury, and asteroids 433 Eros, 4 Vesta, and 1 Ceres. The mid 2020s will see a new generation of spectrometers launch to continue our exploration of the Moon, and to conduct new explorations the metallic asteroid 16 Psyche, Mars' moon Phobos, and Saturn's moon Titan. These instruments will provide the first laboratory-quality measurements from other solar system objects. This success has led to a new challenge, as the accuracy and quality of the underyling nuclear datasets used for interpreting the data are now the limiting factor in our ability to confidently report near-surface composition. A new collaboration between planetary scientists and nuclear physicists is required to address this challenge. I will provide an overview of planetary nuclear spectroscopy measurements, discuss the exciting upcoming science investigations across our solar system, and detail ongoing and needed nuclear data activities that are required to advance the field.