Enceladus is one of the most enigmatic worlds in our solar system. This small, icy moon of Saturn orbits very close to the giant planet, within its E ring. Although it is only about 500 kilometers (310 miles) across, Enceladus is one of the brightest objects in our solar system. Its surface is covered with fresh, white snow that reflects almost all of the sunlight that falls on it.
But there is more to this little world than meets the eye. In 2005, NASA’s Cassini spacecraft made a startling discovery: jets of water vapor and ice were spewing from fissures near the south pole of Enceladus. These geysers are fed by a subsurface ocean of liquid water, making Enceladus one of the few places in our solar system where we know for sure that there is liquid water present.
The discovery of an active water cycle on Enceladus was a major breakthrough in our understanding of this small world. It also raised tantalizing questions about whether life could exist on this tiny moon. After all, wherever there is liquid water and energy (in the form of heat), there is a potential for life as we know it.
Since the initial discovery, Cassini has made multiple flybys of Enceladus, gathering data about its surface features and environment. We now know that the jets are fed by a global ocean beneath Enceladus’s icy crust. This ocean likely contains significant amounts of dissolved methane and other organic molecules—the “building blocks” for life as we know it.
In addition to its potential habitability, Enceladus is also one of the best places in our solar system to study how planets form and evolve over time. Its surface features provide clues about its interior structure and composition, while its unique orbit can tell us much about Saturn’s formation history and dynamics. With continued study, Enceladus has the potential to teach us even more about our solar system—and perhaps even give us insights into how common habitable worlds might be elsewhere in the universe