The May 2024 Superstorm Coronal Mass Ejections as Observed by the Psyche Gamma‐Ray and Neutron Spectrometer

We report new measurements of high‐energy protons ejected by the sun during the May 2024 Ganon superstorm. Our observations were made by the Neutron Spectrometer (NS) on the Psyche spacecraft, which was located at a solar distance of approximately 2 AU and a Sun‐Earth‐Probe separation angle of 75°. This unique vantage point can provide new insights into the nature of this exceptional space weather event. Our observations validated predictions from the WSA‐ENLIL heliospheric model, which forecasted that the Psyche spacecraft would be magnetically‐connected to the Coronal Mass Ejection (CME) on May 10th–11th, and that the Psyche spacecraft would pass through the periphery of the proton‐rich region driven by the superstorm's CME on May 13th. This agreement both validates the large‐scale CME propagation predicted by ENLIL and underscores the value of observations from a variety of geometries. The Psyche spacecraft will continue to make unique observations of solar particle events throughout its interplanetary cruise to asteroid 16 Psyche. We believe that these observations will be a valuable resource for refining particle‐transport models and improving forecasts of solar energetic proton arrival times and intensities.