In a research paper appearing in the current issue of this journal, Max Wallis and Chandra Wickramasinghe have raised the issue of life in the Kuiper belt objects. Hitherto hazy images of Pluto have come into much sharper focus following the New Horizon Spacecraft’s closest approach to this dwarf planet last month. Far from being a dead hard frozen world, Pluto has revealed the most astonishing set of features – exceptionally low levels of cratering, high mountains and smooth plains, and a network of surface cracks. The existence of pigments (colours), organic molecules including methane all point to subsurface biology, according to the authors. Bodies of waters tens of kilometres below the frozen surface could be maintained warm and liquid due to radiogenic heat sources augmented by the metabolic heat of microbial activity. Wickramasinghe told the journal “There is every indication that the evolution of Pluto’s crust, including episodes of mountain building, was largely controlled by biology. The authors conclude: “The New Horizons mission over-fulfils expectations in initiating astrobiological explorations of the new worlds of dwarf planets.”