The survey of works, models and materials in Robert Smithson: Time Crystals at MUMA is a fascinating opportunity not simply to view Smithson’s work, but also to reflect on his methods and theories. The exhibition draws upon Chris McAuliffe and Amelia Barikin’s deep and longstanding interest in Smithson and the legacy of his notions of planetary and geological temporality in shaping physical construction (and hence, sculpture as we knew it). A key feature of the exhibition is the framing of the MUMA site with two darkened chambers, each exhibiting a projection of a landmark land art film: Robert Smithson’s Spiral Jetty (1970) and Nancy Holt and Robert Smithson’s Swamp (1971). Their conjoined audio lightly floats throughout the other five chambers.