Earth might be the showiest blue marble, but Jupiter’s moons Europa and Ganymede, Saturn’s moons Enceladus and Titan, and more objects in the outer solar system have turned out to be remarkably active ocean worlds. Their interiors are filled with exotic forms of ice and vast seas of water. They may have hydrothermal vents feeding into oceans. All of these characteristics add up to potential habitability. The driver for much of this dynamism is volcanism. The mix of heat, water, ice, and rock makes these worlds fascinating to planetary and Earth scientists alike. Could these icy, volcanic moons host life? What does it take to create habitable zones in the outer solar system? One of the scientists interviewed for their thoughts on this is Jennifer Glass, associate professor in the School of Earth and Atmospheric Sciences.