Rate My Professor Ian Crossfield

Ian J.M. Crossfield serves as Associate Professor in the Department of Physics and Astronomy at the University of Kansas, leading the KU ExoLab, a research group dedicated to the discovery and characterization of nearby planetary systems through photometry and high-resolution spectroscopy from ground- and space-based observatories. He obtained his Ph.D. in Astrophysics from the University of California, Los Angeles in 2012 with a dissertation on infrared observations of exoplanet atmospheres, an M.S. in Astrophysics from UCLA in 2009, and a B.S. in Physics magna cum laude from the University of California, Irvine in 2004. Crossfield's professional trajectory includes Assistant Professor at the Massachusetts Institute of Technology Department of Physics from 2017 to 2019, Assistant Professor and then Associate Professor at the University of Kansas from 2020 to present, Sagan Fellowship at the University of California, Santa Cruz from 2016 to 2017 and at the University of Arizona Lunar and Planetary Laboratory from 2014 to 2016, Postdoctoral Fellowship at the Max Planck Institute for Astronomy from 2012 to 2014, and Systems Engineer at NASA's Jet Propulsion Laboratory from 2004 to 2007.

His research centers on exoplanet formation, composition, detection, and characterization. Notable achievements include the first James Webb Space Telescope detection of carbon dioxide in an exoplanet atmosphere, confirmation of the first planet orbiting a white dwarf, and leadership of the OrCAS survey on the origins, compositions, and atmospheres of sub-Neptunes. Key publications include "OrCAS: Origins, Compositions, and Atmospheres of Sub-neptunes. I. Survey Definition" (2025, Astronomical Journal), "Mapping the SO2 Shoreline in Gas Giant Exoplanets" (2025), "Volatile-to-sulfur Ratios Can Recover a Gas Giant’s Accretion History" (2023, Astrophysical Journal Letters), "GJ 1252b: A Hot Terrestrial Super-Earth with No Atmosphere" (2022, Astrophysical Journal Letters), "A global cloud map of the nearest known brown dwarf" (2014, Nature), and the invited review "Observations of Exoplanet Atmospheres" (2015, Publications of the Astronomical Society of the Pacific). Crossfield has received the NASA Sagan Fellowship in 2014, Kavli Frontiers of Science Fellowship in 2015, AAS Doxsey Prize in 2013, and multiple AAS Chambliss Student Achievement Awards. He chairs the NASA Exoplanet Exploration Program Analysis Group Executive Committee since 2025, serves on the National Academies Committee on Astronomy and Astrophysics, and has given invited public lectures on exoplanet astronomy and the James Webb Space Telescope.