4. The Ice Shells of Enceladus
Saturn’s moon Enceladus has captured scientific curiosity with dramatic watery plumes erupting from its south pole. These jets hint at a hidden ocean beneath the moon’s thick ice shell. The Cassini spacecraft made a remarkable discovery—organic molecules within these plumes—raising the possibility of life thriving in the dark, salty waters below. Enceladus is now considered a prime target in the search for alien life, as its conditions may resemble those where life began on Earth. Learn more from NASA.