LPI Welcomes McKay Postdoctoral Fellow Sam Crossley
May 12, 2022
Recently, LPI welcomed Dr. Sam Crossley as the new McKay Postdoctoral Fellow. Dr. Crossley is a planetary petrologist/geochemist/spectroscopist. He is interested in understanding how the different bulk chemistries of parent bodies inherited from their various reservoirs during early solar system history can affect their subsequent evolutionary pathways (e.g., planetary differentiation). His current work investigates how core formation may have occurred in oxidized, sulfur-rich asteroids in lieu of significant quantities of metal. This investigation utilizes a cross-disciplinary approach that includes the fields of experimental petrology, trace element geochemistry, stable isotope geochemistry, and mineral physics within LPI, NASA Johnson Space Center, and other institutions abroad.
Sam celebrating with his host family during Peace Corps training in Sierra Leone before moving to Kamakwie village to teach science and math for two years (2011-2013).
Sam visiting Hamilton Pool Preserve with his wife, Kanu (2020).
LPI: When did you know that you wanted to pursue this as a career?
SC: When I returned home from service, I learned that there was a world-class meteorite museum in my hometown. I met with the curator of the Monnig Meteorite Gallery, Dr. Rhiannon Mayne. She showed me the meteorite vault, FULL of the most bizarre and beautiful rocks I had ever seen. She put one small rock in each of my palms and told me that I was holding both the Moon and Mars. I left the vault knowing what career I wanted. What other choice did she leave me?
LPI: What is the focus of your research?
SC: I want to understand the earliest stages of planetary differentiation, which is when planets begin to melt and evolve into their familiar layered structures of rocky crusts, mantles, and metallic cores. Currently, I’m working to understand how core formation occurs within oxygen-rich asteroids that initially lack metal. I use melting experiments with meteorites and synthetic analogs to explore these processes both mineralogically and geochemically. There is so much we don’t know about the diversity of planetary materials in the solar system, and I’m excited to explore the possibilities for what’s out there.