[meteorite-list] Cassini Observes Meteors Colliding With Saturn's Rings

From: Michael Mulgrew <mikestang_at_meteoritecentral.com>
Date: Thu, 25 Apr 2013 12:39:09 -0700
Message-ID: <CAMseTy3BOY5X1zNHBqczGre_Bv+tQGLDa55tfbqxF4kex+wOfg_at_mail.gmail.com>

A "meteor" can't collide with anything!

Michael in so. Cal.

On Thu, Apr 25, 2013 at 12:34 PM, Ron Baalke <baalke at zagami.jpl.nasa.gov> wrote:
>
>
>
> April 25, 2013
>
> Dwayne Brown
> Headquarters, Washington
> 202-358-1726
> dwayne.c.brown at nasa.gov
>
> Jia-Rui C. Cook
> Jet Propulsion Laboratory, Pasadena, Calif.
> 818-354-0850
> jccook at jpl.nasa.gov
>
> RELEASE: 13-120
>
> NASA PROBE OBSERVES METEORS COLLIDING WITH SATURN'S RINGS
>
> WASHINGTON -- NASA's Cassini spacecraft has provided the first direct
> evidence of small meteoroids breaking into streams of rubble and
> crashing into Saturn's rings.
>
> These observations make Saturn's rings the only location besides
> Earth, the moon, and Jupiter where scientists and amateur astronomers
> have been able to observe impacts as they occur. Studying the impact
> rate of meteoroids from outside the Saturn system helps scientists
> understand how different planet systems in the solar system formed.
>
> Our solar system is full of small, speeding objects. Planetary bodies
> frequently are pummeled by them. The meteoroids at Saturn range from
> about one-half inch to several yards (1 centimeter to several meters)
> in size. It took scientists years to distinguish tracks left by nine
> meteoroids in 2005, 2009 and 2012.
>
> Details of the observations appear in a paper in the Thursday edition
> of Science.
>
> Results from Cassini already have shown Saturn's rings act as very
> effective detectors of many kinds of surrounding phenomena, including
> the interior structure of the planet and the orbits of its moons. For
> example, a subtle but extensive corrugation that ripples 12,000 miles
> (19,000 kilometers) across the innermost rings tells of a very large
> meteoroid impact in 1983.
>
> "These new results imply the current-day impact rates for small
> particles at Saturn are about the same as those at Earth-- two very
> different neighborhoods in our solar system, and this is exciting to
> see," said Linda Spilker, Cassini project scientist at NASA's Jet
> Propulsion Laboratory (JPL) in Pasadena, Calif. "It took Saturn's
> rings acting like a giant meteoroid detector -- 100 times the surface
> area of the Earth -- and Cassini's long-term tour of the Saturn
> system to address this question."
>
> The Saturnian equinox in summer 2009 was an especially good time to
> see the debris left by meteoroid impacts. The very shallow sun angle
> on the rings caused the clouds of debris to look bright against the
> darkened rings in pictures from Cassini's imaging science subsystem.
>
> "We knew these little impacts were constantly occurring, but we didn't
> know how big or how frequent they might be, and we didn't necessarily
> expect them to take the form of spectacular shearing clouds," said
> Matt Tiscareno, lead author of the paper and a Cassini participating
> scientist at Cornell University in Ithaca, N.Y. "The sunlight shining
> edge-on to the rings at the Saturnian equinox acted like an
> anti-cloaking device, so these usually invisible features became
> plain to see."
>
> Tiscareno and his colleagues now think meteoroids of this size
> probably break up on a first encounter with the rings, creating
> smaller, slower pieces that then enter into orbit around Saturn. The
> impact into the rings of these secondary meteoroid bits kicks up the
> clouds. The tiny particles forming these clouds have a range of
> orbital speeds around Saturn. The clouds they form soon are pulled
> into diagonal, extended bright streaks.
>
> "Saturn's rings are unusually bright and clean, leading some to
> suggest that the rings are actually much younger than Saturn," said
> Jeff Cuzzi, a co-author of the paper and a Cassini interdisciplinary
> scientist specializing in planetary rings and dust at NASA's Ames
> Research Center in Moffett Field, Calif. "To assess this dramatic
> claim, we must know more about the rate at which outside material is
> bombarding the rings. This latest analysis helps fill in that story
> with detection of impactors of a size that we weren't previously able
> to detect directly."
>
> The Cassini-Huygens mission is a cooperative project of NASA, the
> European Space Agency and the Italian Space Agency. JPL manages the
> Cassini-Huygens mission for NASA's Science Mission Directorate in
> Washington. JPL designed, developed and assembled the Cassini orbiter
> and its two onboard cameras. The imaging team consists of scientists
> from the United States, England, France and Germany. The imaging
> operations center is based at the Space Science Institute in Boulder,
> Colo.
>
> For images of the impacts and information about Cassini, visit:
>
> http://www.nasa.gov/cassini
>
> -end-
>
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Received on Thu 25 Apr 2013 03:39:09 PM PDT