In this paper I argue that discussion about the ‘technosphere’ as an emergent new Earth system needs to be situated within wider reflection about how technospheres might arise on other worlds. Engaging with astrobiological speculation about ‘exo-technospheres’ can help us to understand whether technospheres are likely, what their preconditions might be, and whether they endure. Engaging with science fiction can help us to avoid observer biases that encourage linear assumptions about the preconditions and emergence of technospheres. Exploring earlier major transitions in Earth’s evolution can shed light on the shifting distribution of metabolic and reproductive powers between the human and technological parts of the contemporary technosphere. The long-term evolution of technical objects also suggests that they have shown a tendency to pass through their own major transitions in their relation to animality. Such reflection can shed new light on the nature and likely future development of the Earth’s technosphere.