On October 14th, 2015 Cassini flew within 1,142 miles of Saturn’s moon Enceladus to catch the first-ever close up picture of its north pole.
Two more Enceladus fly-bys are planned, one in a few weeks and one in mid-December. These will be the last visits to Enceladus for Cassini whose mission ends in 2017.
The October 28th pass will come within 30 miles of Enceladus and has an ambitious goal. To quote NASA:
“During this encounter, Cassini will make its deepest-ever dive through the moon’s plume of icy spray, collecting images and valuable data about what’s going on beneath the frozen surface. Cassini scientists are hopeful data from that flyby will provide evidence of how much hydrothermal activity is occurring in the moon’s ocean, and how the amount of activity impacts the habitability of Enceladus’ ocean.”
There is probably a less dramatic, more understated way to describe an upcoming event of such potential importance but thankfully I am unaware of it.
Think of what is happening! Since the plumes were discovered by Cassini in 2005 and raised the possibilities of thermal life-generating activity in the waters of Enceladus, we have not been able to do much more than wonder about their composition.
In a few weeks Cassini with its spectrometers, dust collector and particle analyzer will fly through this mix and perhaps tell us something about what’s happening in an ocean on another world.
No doubt NASA is right not to raise expectations. But the possibilities are exciting!