* Astronomy

This map of the south polar region of Saturn's moon Enceladus shows the correlation between jet sources identified in Cassini imaging data and hot spots on the surface located by the composite infrared spectrometer instrument.
To identify jet source locations on the surface, imaging scientists carefully measured the locations and orientations of individual jets observed along the moon's limb in Cassini images taken from multiple viewing angles. For each jet measurement, the researchers then computed a curve, or ground track, on the surface of Enceladus along which that jet might lie. The ground tracks from all of the measurements made in the various images produced many intersections on this map. By considering the jet directions at every possible intersection, the researchers isolated eight clusters of ground track intersections as jet sources.


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Credit NASA

The eight identified jet source locations are labelled with yellow roman numerals. Composite infrared spectrometer hot spots are red boxes labelled with green capital letters. The line-of-sight intersections indicating the measurements of each source in individual images are shown as coloured diamonds. White circles indicate the uncertainty in the locations of those sets of intersections.
The map is a polar stereographic projection of Cassini imaging data. The four tiger stripe fractures, or sulci, are labelled here. The south pole is dead centre on the map. Key longitudes are also labelled around the perimeter of the map.

Tiny grains of ice or particles of space dust could significantly damage the Cassini spacecraft when it passes close by Saturns moon Enceladus next March, scientists said Thursday.
Images from Cassini beamed back to Earth in 2005 showed multiple jets emanating from the moons south polar region that scientists suspect arise from warm fractures, known as tiger stripes.

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This nearly equatorial mage of Enceladus was taken in polarised green light with the Cassini spacecraft narrow-angle camera on June 28, 2007, when it was approximately 293,000 kilometres away.


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Credit: NASA/JPL/Space Science Institute

North on Enceladus is up.

The movie was created from 40 original images taken over the course of about 20 minutes as the spacecrafts narrow angle camera remained pointed toward Enceladus. Additional frames were inserted between the 40 Cassini images in order to smooth the appearance of the moons movement.
As Enceladus  approaches Rhea, the shadow of Saturn can be seen, projected onto the unlit side of its  rings.



The images were taken in visible light with the Cassini spacecraft narrow-angle camera on March 2, 2006 at a distance of approximately 2.8 million kilometres  from Rhea and 2 million kilometres from Enceladus. Image scale is 17 kilometres per pixel on Rhea and 12 kilometres  per pixel on Enceladus.

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