Cosmic rays could, in theory, sustain life on other worlds

Cosmic rays may enable microbial life beyond traditional habitable zones through radiolysis, splitting underground water molecules to create energy sources for microbes. Calculations suggest Saturn's moon Enceladus could support the most cells, followed by Mars and Europa. This expands potential habitable areas to include frigid rogue planets, creating a "radiolytic habitable zone." However, such environments would likely host only simple, sparse microbes rather than thriving ecosystems.