[meteorite-list] NASA's Hubble Captures First Images Of Aftermath Of Possible Asteroid Collision

From: Mark Abbott <Mark_at_meteoritecentral.com>
Date: Thu, 14 Oct 2010 16:00:23 -0500
Message-ID: <4CB76F67.5060900_at_MOR-Designs.com>

  Several months ago I read an article which gave migration times of
material from a given orbit to the earth. Can anyone point me towards an
answer, or provide the answer. I specifically am interested in how soon
the material from this collision could find its way to Earth... tens of
thousands of years; millions of years?

Mark

On 10/13/2010 3:34 PM, Ron Baalke wrote:
> Oct. 13, 2010
>
> J.D. Harrington
> Headquarters, Washington
> 202-358-5241
> j.d.harrington at nasa.gov
>
> Donna Weaver
> Space Telescope Science Institute, Baltimore
> 410-338-4493
> dweaver at stsci.edu
>
> David Jewitt
> University of California, Los Angeles
> 310-825-2521
> jewitt at ucla.edu
>
>
> RELEASE: 10-253
>
> NASA'S HUBBLE CAPTURES FIRST IMAGES OF AFTERMATH OF POSSIBLE ASTEROID COLLISION
>
> WASHINGTON -- NASA's Hubble Space Telescope has captured the first
> snapshots of a suspected asteroid collision. The images show a
> bizarre X-shaped object at the head of a comet-like trail of
> material.
>
> In January, astronomers began using Hubble to track the object for
> five months. They thought they had witnessed a fresh asteroid
> collision, but were surprised to learn the collision occurred in
> early 2009.
>
> "We expected the debris field to expand dramatically, like shrapnel
> flying from a hand grenade," said astronomer David Jewitt of the
> University of California in Los Angeles, who is a leader of the
> Hubble observations. "But what happened was quite the opposite. We
> found that the object is expanding very, very slowly."
>
> The peculiar object, dubbed P/2010 A2, was found cruising around the
> asteroid belt, a reservoir of millions of rocky bodies between the
> orbits of Mars and Jupiter. It is estimated modest-sized asteroids
> smash into each other about once a year. When the objects collide,
> they inject dust into interplanetary space. But until now,
> astronomers have relied on models to make predictions about the
> frequency of these collisions and the amount of dust produced.
>
> Catching colliding asteroids is difficult because large impacts are
> rare while small ones, such as the one that produced P/2010 A2, are
> exceedingly faint. The two asteroids that make up P/2010 A2 were
> unknown before the collision because they were too faint to be
> noticed. The collision itself was unobservable because of the
> asteroids' position in relation to the sun.
>
> About 10 or 11 months later, in January 2010, the Lincoln Near-Earth
> Research (LINEAR) Program Sky Survey spotted the comet-like tail
> produced by the collision. But only Hubble discerned the X pattern,
> offering unequivocal evidence that something stranger than a comet
> outgassing had occurred.
>
> Although the Hubble images give compelling evidence for an asteroid
> collision, Jewitt says he still does not have enough information to
> rule out other explanations for the peculiar object. In one such
> scenario, a small asteroid's rotation increases from solar radiation
> and loses mass, forming the comet-like tail.
>
> "These observations are important because we need to know where the
> dust in the solar system comes from, and how much of it comes from
> colliding asteroids as opposed to 'outgassing' comets," Jewitt said.
> "We also can apply this knowledge to the dusty debris disks around
> other stars, because these are thought to be produced by collisions
> between unseen bodies in the disks. Knowing how the dust was produced
> will yield clues about those invisible bodies."
>
> The Hubble images, taken from January to May 2010 with the telescope's
> Wide Field Camera 3, reveal a point-like object about 400 feet wide,
> with a long, flowing dust tail behind a never-before-seen X pattern.
> Particle sizes in the tail are estimated to vary from about 1/25th of
> an inch to an inch in diameter.
>
> The 400-foot-wide object in the Hubble image is the remnant of a
> slightly larger precursor body. Astronomers think a smaller rock,
> perhaps 10 to 15 feet wide, slammed into the larger one. The pair
> probably collided at high speed, about 11,000 mph, which smashed and
> vaporized the small asteroid and stripped material from the larger
> one. Jewitt estimates that the violent encounter happened in February
> or March 2009 and was as powerful as the detonation of a small atomic
> bomb.
>
> Sunlight radiation then swept the debris behind the remnant asteroid,
> forming a comet-like tail. The tail contains enough dust to make a
> ball 65 feet wide, most of it blown out of the bigger body by the
> impact-caused explosion. The science journal Nature will publish the
> findings in the Oct. 14 issue.
>
> "Once again, Hubble has revealed unexpected phenomena occurring in our
> celestial 'back yard," said Eric Smith, Hubble Program scientist at
> NASA Headquarters in Washington. "Though it's often Hubble's deep
> observations of the universe or beautiful images of glowing nebulae
> in our galaxy that make headlines, observations like this of objects
> in our own solar system remind us how much exploration we still have
> to do locally."
>
> Astronomers do not have a good explanation for the X shape. The
> crisscrossed filaments at the head of the tail suggest that the
> colliding asteroids were not perfectly symmetrical. Material ejected
> from the impact, therefore, did not make a symmetrical pattern, a bit
> like the ragged splash made by throwing a rock into a lake. Larger
> particles in the X disperse very slowly and give this structure its
> longevity.
>
> Astronomers plan to use Hubble again next year to view the object.
> Jewitt and his colleagues hope to see how far the dust has been swept
> back by the sun's radiation and how the mysterious X-shaped structure
> has evolved.
>
> For images, movies, and more information about asteroid encounter
> P/2010 A2, visit:
>
> http://hubblesite.org/news/2010/34
>
> and
>
> http://www.nasa.gov/hubble
>
> -end-
>
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Received on Thu 14 Oct 2010 05:00:23 PM PDT