NASA, looking at ways to get boots on Saturn's moon, so to speak, is imagining a robot that would make use of a power source that's been around for more than a century — steam. The robot, called Steam Propelled Autonomous Retrieval Robot for Ocean Worlds, or SPARROW for short, would be able to hop about on Enceladus, one of Saturn's 82 moons.

Enceladus is of particular interest to NASA because there is an ocean of salty liquid under its crust — one that is thought to vent water vapor outward across its icy surface. And that's where SPARROW comes into play.

The robot, which in concept is shaped a bit like a ball, would use water from melted ice on Enceladus' surface, heat that, and from the steam be able to hop about across the moon. NASA even imagines multiple SPARROWs jumping on the moon's surface to collect data about this Saturn satellite.

Just in concept phase right now, the robot has been given some funding from the NASA Innovative Advanced Concepts (NIAC), which looks for potentially new ideas that could be help space missions in the future. Researchers at Jet Propulsion Laboratory are leading the exploration in SPARROW and how it might move, operate and eventually look.

Enceladus has been captivating to planetary scientists and astronomers for years, particularly after close-up views of the very tiny moon (just 500 kilometers in diameter) were captured by the spacecraft Cassini, taking photographs which showed not just cracks along its surface, but jets of water and gases.

As for SPARROW, researchers are still look at how the robot could move, who may be eligible for additional funding to pursue this concept further.