CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Simulations of the Tendrils

This collage, consisting of two Cassini images of long, sinuous, tendril-like features from Saturn's moon Enceladus and two corresponding computer simulations of the same features, illustrates how well the structures, and the sizes of the particles composing them, can be modeled by tracing the trajectories of tiny, icy grains ejected from Enceladus' south polar geysers.

The figures labeled "a" and "c" are computer-enhanced images of the tendril structures near Enceladus that were taken at high solar phase angle (174 and 170 degrees, respectively); figures "b" and "d" are synthetic (computer-generated) images produced by following the trajectories of tiny, icy particles ejected from the 36 most active geysers (representing the top 50 percent of the moon's total geysering activity) found on the south polar terrain. The match between real and synthetic images is quite good and strongly supports the suggestion that tendrils are produced by the moon's geysers.

Electromagnetic effects associated with electrical charges that collect on small grains embedded in a magnetosphere like Saturn's can modify the grains' trajectories. These effects are very sensitive to particle size, with smaller particles feeling the effects of charging more strongly than larger ones. The scale of the arc-like structures seen in the tendrils allows scientists to determine that the tendril particles are no smaller than about 0.5 microns (a micron is one millionth of a meter), a size consistent with that of E-ring particles found from other Cassini observations, both imaging and in situ.

Figure "a" is from the observation of 2006; "c" was taken on July 19, 2013 during Cassini's Earth-imaging event (see PIA17172). Orbital motion is counter-clockwise in all images.

This graphic was one that helped scientists trace the source of the tendrils as described in a paper by Mitchell, Porco and Weiss, published in the online version of the Astronomical Journal in April 2015:

The Cassini Solstice Mission is a joint United States and European endeavor. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini Solstice Mission visit, and

Credit: NASA/JPL-Caltech/SSI
Released: April 14, 2015 (PIA 17191)
Image/Caption Information
  Simulations of the Tendrils
PIA 17191

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Simulations of the Tendrils
PIA 17191

Avg Rating: 10/10

Unannotated Full Size 1024x1024:
PNG 972 KB