Field sites on Earth and, after a fashion, Mars are where geologist Alan Gillespie studied glacial geology and landscape evolution. Terrestrially, he worked primarily in Central Asia, investigating the properties of glacial advance across the region. Extraterrestrially, he and his collaborators investigated the origins of the giant canyons in the Valles Marineris system in the Martian highlands. Gillespie’s work has been recognized for its excellence throughout his career, and he recently the Don J. Easterbrook Distinguished Scientist Award from the Geological Society of America.