At the time of its 1997 launch, NASA’s Cassini spacecraft was among the most advanced space exploration tools ever built, but after nearly twenty years of exploring our solar system, its fuel reserves are nearly depleted.  Like it or not, Cassini’s days of sending back data about the heavenly bodies littering our celestial neighborhood are numbered… the only question is, what now?

In the past, satellites that have run their course have often been permitted to maintain an orbit around their final destinations.  The Dawn spacecraft, for instance, can still be found orbiting the dwarf planet Ceres it last explored.  Cassini’s space-address in orbit around Saturn, however, presents NASA with a difficult decision to make.

Unlike Ceres, Saturn could be considered a system unto itself.  With fifty-three named moons, and rings composed of tiny particles that could likely have been more, orbiting Saturn would be risky business for a spacecraft that is no longer able to produce any of its own thrust.  Chances are good that the Cassini spacecraft could find its orbit shifted by any number of orbital bodies, eventually sending it into a collision course with the planet or one of its moons.

For the most part, that wouldn’t necessarily matter once the craft is no longer operable, but there’s one more important element to address: what if one of Saturn’s icy moons actually harbors life?