This May Be the Closest Look We Get of Saturn’s Moon Enceladus for Decades
NASA's Cassini orbiter sent back the first images from its daring flyby.
Enceladus in Cassini’s rearview mirror. Image: NASA/JPL-Caltech/Space Science Institute
The spacecraft's trajectory brought it within a record-breaking 30 miles of Enceladus's south pole on Wednesday, resulting in the most detailed images of the moon's surface ever captured.
The above image was taken from an altitude of 77 miles, and reveals the complex latticework of the moon's geologically active surface. These patterns are thought to be shaped by Enceladus's active cryovolcanoes, which frequently belch the contents of the moon's subsurface ocean out into deep space in long misty plumes.
Cassini sampled some of this fine spray during its Wednesday flyby, and the orbiter is currently analyzing the results. In particular, the Cassini team is looking for the presence of molecular hydrogen, which would be a good indication that hydrothermal activity is occurring in the depths of Enceladus's icy ocean.
Finding this kind of evidence would boost the likelihood that Enceladus might support life, in much the same way that hydrothermal vents in Earth's oceans host complex ecosystems. Since the flyby marked the team's last opportunity to snatch a whiff of the moon's plumes for a long time, researchers are eagerly anticipating the new findings.
"I think we'll get superb data, and I'm looking forward to discovering some new molecules in the plume, and some new things about the icy grains that are there," Jonathan Lunine, a planetary scientist at Cornell and a Cassini's science team member, told Spaceflight Now.
"It's going to be really high quality data, better than we've gotten before."
Cassini is scheduled to make one last flyby of Enceladus on December 19, but this time it will be passing by at a much less intimate distance of 3,106 miles. From there, the orbiter will say its final goodbyes to the many worlds of the Saturnian system before plunging into the depths of the gas giant itself in 2017.
It is somewhat bittersweet that these stunning snapshots from the latest flyby represent our last close-up glimpse of this curious world, perhaps for decades. But on the other hand, the countless discoveries Cassini has made while exploring Saturn suggest that we have barely begun to scratch the surface of this planetary system's treasures. Whatever the orbiter has to say about Enceladus's interior over the coming weeks will only serve to further illustrate the need for another mission to replace Cassini, so that we can probe even deeper into Saturn's inexhaustible list of mysteries.