We are delighted to announce the selections for the 2025 Pellas-Ryder Award. This award is jointly sponsored by the Meteoritical Society and the Planetary Geology Division of the Geological Society of America and honors outstanding first author planetary science papers by students.
Alexander Kling, who is a graduate student at Purdue University, West Lafayette, IN, USA, is the co-winner of the 2025 Pellas-Ryder Award for the paper entitled Nanoscale reservoirs store solar wind-derived water on the lunar surface published in Earth and Planetary Science Letters. This work describes detailed analyses of solar wind-derived hydrogen and water in the space weathered rims of small lunar grains returned by the Apollo 17 mission. Using correlated nanoscale observations, the paper shows that hydrogen and water can be trapped in vesicles formed by solar wind irradiation, providing proof of the mechanism to form solar wind-derived water of the Moon. These observations help explain the behavior and long-term storage of solar wind volatiles on the lunar surface.The committee were impressed by the highly novel and complex analytical work and the excellent presentation and description of the data.
Ian Pamerleau, who is a graduate student at Purdue University, West Lafayette, IN, USA, is the co-winner of the 2025 Pellas-Ryder Award for the paper entitled An ancient and impure frozen ocean on Ceres implied by its ice-rich crust published in Nature Astronomy. The paper reports a modelling approach to solving the mystery of Ceres’ internal structure. Unlike previous studies, the model considers the effects of impurities in the ice and demonstrates how Ceres can have both an ice-rich crust and heavily cratered surface, satisfying multiple datasets collected by NASA’s Dawn mission. In particular, the committee praised the clear aims and objectives of the paper and the wider implications it has for understanding icy bodies in the Solar System.
Congratulations to the 2025 co-winners for this highly deserved honor and for leading these impressive studies! We also thank everyone who submitted nomination packages and the Pellas-Ryder Award Committee for their work to make this award possible.
Based on reports submitted by: Ashley King, 2025 Pellas-Ryder Award Committee Chair