This article develops a speculative approach to thinking about the temporalities of ice.Examining the politics of ice cores as temporal probes, it argues that ice comes to matterin political and ecological terms and as the very "stuff of time". As cylinders of ice thatare extracted through drilling into the deep time of extreme cryogenic environments, icecores become speculative devices to conceive of climates past and future. An analysisof ice-coring practices and technologies as time capsules or temporal probes allowsfor a novel way of thinking about the temporal materialities of ice and its vibrancies anddistributive agency, and how the material-semiotic entanglements of ice-coring practicesbecome a way of listening to the call of matter.