[meteorite-list] Cassini Flies Through Watery Plumes of Saturn Moon Enceladus

From: Michael Murray <mmurray_at_meteoritecentral.com>
Date: Fri, 14 Mar 2008 18:50:46 -0600
Message-ID: <6AE566B9-9F84-4406-8AB0-89638D8567CC_at_montrose.net>

You gotta love Enceladus. Bright white with at least five different
types of terrain on it but mostly looks to be one huge ice ball.
How in seven suns did it establish itself as a satellite of Saturn?
I'm anxious to hear more about the analysis of the geysers.

Thanks Mr. Baalke for the updates. Most interesting.

Mike Murray
micro hunter of southwest Colorado

On Mar 14, 2008, at 4:43 PM, Ron Baalke wrote:

>
> http://www.jpl.nasa.gov/news/news.cfm?release=2008-044
>
> Cassini Flies Through Watery Plumes of Saturn Moon
> Jet Propulsion Laboratory
> March 13, 2008
>
> NASA's Cassini spacecraft performed a daring flyby of Saturn's moon
> Enceladus on Wed., March 12, flying about 15 kilometers per second
> (32,000 mph) through icy water geyser-like jets. The spacecraft
> snatched
> up precious samples that might point to a water ocean or organics
> inside
> the little moon.
>
> Scientists believe the geysers could provide evidence that liquid
> water
> is trapped under the icy crust of Enceladus. The geysers emanate from
> fractures running along the moon's south pole, spewing out water vapor
> at approximately 400 meters per second (800 mph).
>
> The new data provide a much more detailed look at the fractures that
> modify the surface and will give a significantly improved comparison
> between the geologic history of the moon's north pole and south pole.
>
> New images show that compared to much of the southern hemisphere on
> Enceladus--the south polar region in particular--the north polar
> region
> is much older and pitted with craters of various sizes. These craters
> are captured at different stages of disruption and alteration by
> tectonic activity, and probably from past heating from below. Many of
> the craters seem sliced by small parallel cracks that appear to be
> ubiquitous throughout the old cratered terrains on Enceladus.
>
> "These new images are showing us in great detail how the moon's north
> pole differs from the south, an important comparison for working
> out the
> moon's obviously complex geological history," said Carolyn Porco,
> Cassini imaging team leader, Space Science Institute, Boulder, Colo.
> "And the success of yesterday's daring and very low-altitude flyby
> means
> this coming summer's very close encounter, when we get exquisitely
> detailed images of the surface sources of Enceladus' south polar jets,
> should be an exciting 'next big step' in understanding just how the
> jets
> are powered."
>
> This week's flyby and another one planned for Oct. 9, 2008, were
> designed so that Cassini's particle analyzers could dissect the "body"
> of the plume for information on the density, size, composition and
> speed
> of the particles. Among other things, scientists will use the data
> gathered this week to figure out whether the gases from the plume
> match
> the gases that make up the halo of particles around Enceladus. This
> may
> help determine how the plumes formed.
>
> During Cassini's closest approach, two instruments were collecting
> data--the Cosmic Dust Analyzer and the Ion and Neutral Mass
> Spectrometer. An unexplained software hiccup with Cassini's Cosmic
> Dust
> Analyzer instrument prevented it from collecting any data during
> closest
> approach, although the instrument did get data before and after the
> approach. During the flyby, the instrument was switching between two
> versions of software programs. The new version was designed to
> increase
> the ability to count particle hits by several hundred hits per second.
> The other four fields and particles instruments on the spacecraft, in
> addition to the ion and neutral mass spectrometer, did capture all of
> their data, which will complement the overall composition studies and
> elucidate the unique plume environment of Enceladus.
>
> Cassini's instruments discovered evidence for the geyser-like jets on
> Enceladus in 2005, finding that the continuous eruptions of ice water
> create a gigantic halo of ice dust and gas around Enceladus, which
> helps
> supply material to Saturn's E-ring.
>
> This was the first of four Cassini flybys of Enceladus this year.
> During
> Wednesday's flyby, the spacecraft came within 50 kilometers (30 miles)
> of the surface at closest approach, 200 kilometers (120 miles) while
> flying through the plume. Future trips may bring Cassini even
> closer to
> the surface of Enceladus. Cassini will complete its prime mission, a
> four-year tour of Saturn, in June. From then on, a proposed extended
> mission would include seven more Enceladus flybys. The next Enceladus
> flyby would take place in August of this year.
>
> For more images and more information, visit: http://www.nasa.gov/
> cassini
> and http://saturn.jpl.nasa.gov .
>
> The Cassini-Huygens mission is a cooperative project of NASA, the
> European Space Agency and the Italian Space Agency. JPL, a division of
> the California Institute of Technology in Pasadena, manages the
> Cassini-Huygens mission for NASA's Science Mission Directorate,
> Washington. The Cassini orbiter was designed, developed and
> assembled at
> JPL.
>
> ----------------------------------------------------------------------
> --
>
> Media Contact: Carolina Martinez 818-354-9382
> Jet Propulsion Laboratory, Pasadena, Calif.
> carolina.martinez at jpl.nasa.gov
>
> Preston Dyches 720-974-5859
> Space Science Institute, Boulder, Colo.
> media at ciclops.org
>
> 2008-044
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Received on Fri 14 Mar 2008 08:50:46 PM PDT