Subsurface microbiology and the pressing societal need to support future exploration.

Subsurface microbiology is at a crossroads, evolving from asking 'who's home' to seeking clarity on microbes' functionality and the key processes that constrain subsurface life. Importantly, the processes subsurface microorganisms mediate are central to societal needs to mitigate climate change and address waste storage, as proposed solutions to both involve subsurface habitats. However, subsurface sampling opportunities and funding remain limited and, in some cases, have diminished. This perspective article is aimed at scientists who have or might develop an interest in the geomicrobiology of the subsurface, for funding agencies worldwide, and for scientists and engineers engaged in the extractive and waste disposal industries. It briefly reviews subsurface science's history and current status and proposes some actions for moving forward. In particular, we see the continued need for engaging early-career microbiologists in drilling projects, increasing access through industry partnerships, microbiology-led drilling projects, and creating interdisciplinary drilling projects by including microbiologists during the drilling project planning.