Tag Archives: Saturn’s satellite

Shadows and Plumes Across Enceladus 

enceladusshadow_cassini_1016
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

 Why does Enceladus have ice plumes? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, remained a topic of research. A leading hypothesis held that the source might originate from a deep underground sea, but another hypothesis indicated that it might just be ice melted off walls of deep rifts by the moon’s tidal flexing and heating. Pictured above, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. Recent study of over a hundred images like this – of geysers crossing Enceladus’ South Pole, together with regional heat maps, indicate that these plumes likely originate from a hidden sea, incresaing the chance that this frosty globe might be harboring life.

APOD NASA 04-Aug-14

Fresh Tiger Stripes on Saturn’s Enceladus

enceladusstripes_cassini_3237
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Do underground oceans vent through the tiger stripes on Saturn’s moon Enceladus? Long features dubbed tiger stripes are known to be spewing ice from the moon’s icy interior into space, creating a cloud of fine ice particles over the moon’s South Pole and creating Saturn’s mysterious E-ring. Evidence for this has come from the robot Cassini spacecraft now orbiting Saturn. Pictured above, a high resolution image of Enceladus is shown from a close flyby. The unusual surface features dubbed tiger stripes are visible in false-color blue. Why Enceladus is active remains a mystery, as the neighboring moon Mimas, approximately the same size, appearsquite dead. Most recently, an analysis of slight gravity deviations has given an independent indication of underground oceans. Such research is particularly interesting since such oceans would be candidates to contain life.

NASA APOD 06-Apr-14