Galileo’s Final Plunge: A Deliberate Shield for Europa’s Hidden Ocean

NASA steered the Galileo orbiter into Jupiter in 2003 on a controlled, propellant-limited end to prevent possible Earth microbes from contaminating Europa, which magnetic data and geology make a strong case for a deep salty ocean beneath its icy shell. The disposal occurred without sterilization proof, prioritizing future measurements and the protection of a potentially habitable world over extending the mission.