* Astronomy

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RE: Enceladus

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Beams of electrons link Saturn with its moon Enceladus

Data from NASA's Cassini spacecraft have revealed that Enceladus, one of Saturn's diminutive moons, is linked to Saturn by powerful electrical currents - beams of electrons that flow back and forth between the planet and moon. The finding is part of a paper published in Nature today.
CAPS, one of the instruments on board Cassini which made the electron beam discovery, includes a electron sensor called CAPS-ELS - led by UCL (University College London).
Since Cassini's arrival at Saturn in 2004 it has passed 500km-wide Enceladus 14 times, gradually discovering more of its secrets on each visit. Research has found that jets of gas and icy grains emanate from the south pole of Enceladus, which become electrically charged and form an ionosphere. The motion of Enceladus and its ionosphere through the magnetic bubble that surrounds Saturn acts like a dynamo, setting up the newly-discovered current system.

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Cassini Finds Enceladus is a Powerhouse

Heat output from the south polar region of Saturn's moon Enceladus is much greater than was previously thought possible, according to a new analysis of data collected by NASA's Cassini spacecraft. The study was published in the Journal of Geophysical Research on March 4.
Data from Cassini's composite infrared spectrometer of Enceladus' south polar terrain, which is marked by linear fissures, indicate that the internal heat-generated power is about 15.8 gigawatts, approximately 2.6 times the power output of all the hot springs in the Yellowstone region, or comparable to 20 coal-fuelled power stations. This is more than an order of magnitude higher than scientists had predicted, according to Carly Howett, the lead author of study, who is a postdoctoral researcher at Southwest Research Institute in Boulder, Colo., and a composite infrared spectrometer science team member.
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On the heels of a successful close flyby of Saturn's moon Enceladus, NASA's Cassini spacecraft is returning images of Enceladus and the nearby moon Dione.
Several pictures show Enceladus backlit, with the dark outline of the moon crowned by glowing jets from the south polar region. The images show several separate jets, or sets of jets, emanating from the fissures known as "tiger stripes." Scientists will use the images to pinpoint the jet source locations on the surface and learn more about their shape and variability.
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Credit: NASA/JPL/Space Science Institute

This image of Enceladus was taken by the Cassini spaceprobe on the 20th December, 2010, when it was approximately 157919 kilometres away.
The image was taken using the CL1 and CL2 filters.

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Cassini Takes Close-Up of Enceladus Northern Hemisphere

NASA's Cassini spacecraft will be making its close flyby of the northern hemisphere of Saturn's moon Enceladus today, Monday, Dec. 20. The closest approach will take place at 5:08 PM PST (8:08 EST) on Dec. 20, or 1:08 AM UTC on Dec. 21. The spacecraft will zip by at an altitude of about 48 kilometres above the icy moon's surface.
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Cassini Returns Images of Bright Jets at Enceladus

Cassini spacecraft successfully dipped near the surface of Saturn's moon Enceladus on Nov. 30.
NASA's Cassini spacecraft successfully dipped near the surface of Saturn's moon Enceladus on Nov. 30. Though Cassini's closest approach took it to within about 48 kilometres of the moon's northern hemisphere, the spacecraft also captured shadowy images of the tortured south polar terrain and the brilliant jets that spray out from it.
Many of the raw images feature darkened terrain because winter has descended upon the southern hemisphere of Enceladus. But sunlight behind the moon backlights the jets of water vapour and icy particles. In some images, the jets line up in rows, forming curtains of spray.
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Expand (148kb, 1024 x 1024)
Credit: NASA/JPL/Space Science Institute

This image of Enceladus was taken by the Cassini spaceprobe on the 30th November, 2010, when it was approximately 96,418 kilometres away.
The image was taken using the CL1 and CL2 filters.

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Cassini Finds Warm Cracks on Enceladus

New images and data from NASA's Cassini spacecraft give scientists a unique Saturn-lit view of active fissures through the south polar region of Saturn's moon Enceladus. They reveal a more complicated web of warm fractures than previously thought.
Scientists working jointly with Cassini's composite infrared spectrometer and its high-resolution imaging camera have constructed the highest-resolution heat intensity maps yet of the hottest part of a region of long fissures spraying water vapour and icy particles from Enceladus. These fissures have been nicknamed "tiger stripes." Additional high-resolution spectrometer maps of one end of the tiger stripes Alexandria Sulcus and Cairo Sulcus reveal never-before-seen warm fractures that branch off like split ends from the main tiger stripe trenches. They also show an intriguing warm spot isolated from other active surface fissures.
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NASA's Cassini back on track for Nov. 30 flyby

Managers of NASA's Cassini spacecraft mission expect to get a full stream of data during this week's flyby of the Saturnian moon Enceladus, according to a release from Jet Propulsion Laboratory, which manages the mission for NASA. Cassini resumed normal operations last week after going into safe mode on Nov. 2.
The flyby on Nov. 30 will bring Cassini to within about 48 kilometres of the surface of Enceladus. At 61 degrees north latitude, this encounter and its twin three weeks later at the same altitude and latitude, are the closest Cassini will come to the northern hemisphere surface of Enceladus during the extended Solstice mission.
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