Space in Images - 2015 - 11 - Sampling the ocean on Enceladus
▻http://www.esa.int/spaceinimages/Images/2015/11/Sampling_the_ocean_on_Enceladus
© NASA/JPL-Caltech/Space Science Institute
The Cassini spacecraft captured this view of Saturn’s icy moon Enceladus as it approached for its closest-ever flyby of the moon’s active south polar region.
The spacecraft flew about 49 km above the surface through the towering plumes of ice, water vapour and organic molecules spraying from that region. Previous flybys have sampled the plume but the low altitude of this close encounter was devised partly to provide greater sensitivity to heavier, more massive molecules, including organics.
Studies with Cassini have shown that beneath the moon’s icy exterior lies a global ocean heated in part by tidal forces from Saturn and its moon Dione.
Scientists will use the new information gathered during this dive through the plume to gain insights about how habitable the ocean environment may be for simple forms of life, and to study the chemistry and composition of the plume.
In this view of the moon, the heavily cratered northern latitudes at the top transition to fractured, wrinkled terrain in the middle and southern latitudes. The wavy boundary of the moon’s active south polar region – Cassini’s destination for this flyby – is visible at the bottom, where it disappears into wintry darkness.
This image of the Saturn-facing side of the moon was taken with the narrow-angle camera on 28 October 2015 when Cassini was at a distance of some 96 000 km from Enceladus. The image scale is 578 m per pixel.
sur le site du JPL
▻http://photojournal.jpl.nasa.gov/catalog/PIA17202