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Double asteroid belt in Solar System clone

...Spitzer observations have discerned two rocky asteroid belts and an icy outer ring surrounding our Sun’s doppelgänger Epsilon Eridani that could have been shaped by evolving planets..

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Fireball captured by Canadian cameras

...for the second time this year The University of Western Ontario’s Meteor Group has captured rare footage of a meteor streaking across the sky and possibly falling to the ground...

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ESA gravity mission slips to 2009

...the launch of Europe’s Gravity field and steady-state Ocean Circulation Explorer (GOCE) has slipped to February 2009 due to ongoing technical faults with its launcher..

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STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.

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STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.

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STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

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STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.

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Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

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Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

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Cassini’s imaging trick earned halloween treats from Enceladus
BY DR EMILY BALDWIN
ASTRONOMY NOW

Posted: 31 October, 2008; updated 04 November

Following the success of the ‘skeet shoot’ imaging technique employed for the 11 August Enceladus fly-by, Cassini performed the same trick to obtain more high resolution images of the icy satellite this halloween.

Cassini captured more high resolution images of the prominent tiger stripes in the south polar region of Enceladus in a halloween encounter with Saturn’s enigmatic moon. Image: NASA/JPL/Space Science Institute.

While the 9 October fly-by focussed on the geyser-like plumes emanating from the so-called tiger stripes at the moon’s south pole, the halloween fly-by was set on obtaining high resolution images of the terrain from which the jets are erupting. The skeet shoot technique, named after an Olympic shooting event, works by initially pointing Cassini ahead of the moon, and ordering it to track a point in space while it waits for Enceladus to move into the camera’s field of view. Once the targeted region is in the line of fire, the camera shoots images of the high priority target regions in rapid succession.

For the 31 October fly-by, the ground track of the camera's pointing was selected to cut across two tiger stripes, known as sulci. The swath was chosen to pass over three particular segments of the tiger stripes that are known to be local hot spots and which are sites of previously observed eruptions. The results of the fly-by mean that the Cassini team have now observed six of eight jet sources, with the latest fly-by catching sources assigned tags VI and VII in and around the Baghdad sulci, as well as repeating observations of Damascus jet sources II and III. They noted that the region of the active tiger stripes is finely-fractured throughout and littered with icy blocks.

The source region for a jet (assigned the tag VI) was identified in the Baghdad Sulcus region. Image: NASA/JPL/Space Science Institute.

This image was captured at a resolution of just nine metres per pixel, the highest resolution of the halloween encounter. The image shows the south polar terrain in unprecedented detail, revealing fractured terrain littered with icy blocks. Image: NASA/JPL/Space Science Institute.

Related Stories

Oct 13   New views of enigmatic Enceladus... read more

Oct 08   Cassini prepares for double flyby... read more

Aug 28   Cassini pintpoints source of Enceladus jets read more

Aug 13  Enceladus images dazzling success read more

Aug 12  Cassini swoops past Enceladus read more

Jun 02   Cassini primed for extended tour of Saturn read more

May 21  Cassini maps of Saturn’s moons... read more

Mar 27   Cassini tastes organic material... read more

Mar 14   Cassini flyby success read more

Mar 11   Cassini to dive into water plume... read more

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