Galileo’s endgame: NASA crashes the probe to protect Europa’s hidden ocean

NASA kept the Galileo spacecraft alive for 14 years despite a jammed antenna and brutal radiation, then deliberately steered it into Jupiter in 2003 to destroy it—not because it failed but to prevent Earth microbes from contaminating Europa, where data showed a likely subsurface saltwater ocean. The decision cemented planetary protection as a core principle, guiding missions like Europa Clipper and JUICE to study possible ocean worlds without risking contamination, illustrating how discovery can carry protective costs for future exploration.