25. The Subterranean Biosphere
Beneath Earth’s crust lies a thriving subterranean biosphere—microbes that survive on minimal energy and without sunlight. This remarkable discovery expands our understanding of where life can exist and has inspired scientists to search for similar deep biospheres on Mars and other rocky planets. By studying these resilient Earth microbes, researchers hope to unlock secrets about life’s potential to flourish in the darkest, most isolated environments. Explore more at Nature.