[meteorite-list] Giant Asteroid's Troughs Suggest Stunted Planet

From: Michael Murray <mikebevmurray_at_meteoritecentral.com>
Date: Wed, 26 Sep 2012 20:58:19 -0600
Message-ID: <5A0FE80D-5ABC-42C8-8DA6-832C82C61F17_at_gmail.com>

Is it possible they could be a result of the giant impact? Ripples
maybe?

On Sep 26, 2012, at 6:03 PM, Ron Baalke wrote:

>
> http://www.jpl.nasa.gov/news/news.php?release=2012-304
>
> Giant Asteroid's Troughs Suggest Stunted Planet
> Jet Propulsion Laboratory
> September 26, 2012
>
> Enormous troughs that wrap around the giant asteroid Vesta may
> actually
> be dropped blocks of terrain bounded by fault lines, suggesting a
> geologic complexity beyond that of most asteroids. Since the discovery
> of the troughs last year in data from NASA's Dawn spacecraft,
> scientists
> have been working to determine the story behind these unusual
> features.
> The research reinforces the claim that Vesta has a core, mantle and
> crust, a structure normally reserved for larger bodies, such as
> planets
> and large moons.
>
> An extensive system of troughs encircles Vesta's equatorial region.
> The
> biggest of those troughs, named Divalia Fossa, surpasses the size of
> the
> Grand Canyon. It spans 289 miles (465 kilometers) in length, 13.6
> miles
> (22 kilometers) in width and 3 miles (5 kilometers) in depth. The
> complexity of the troughs' morphology can't be explained by small
> collisions. New measurements from Dawn indicate that a large collision
> could have created the asteroid's troughs, said Debra Buczkowski, a
> Dawn
> participating scientist based at the Johns Hopkins University Applied
> Physics Laboratory in Laurel, Md., who is the lead author of a new
> paper
> in Geophysical Research Letters, a journal of the American Geophysical
> Union. The crustal layer at the surface appeared to stretch to the
> breaking point and large portions of the crust dropped down along two
> faults on either side of the downward-moving block, leaving the giant
> troughs we see today.
>
> The scale of the fracturing would only have been possible if the
> asteroid is differentiated - meaning that it has a core, mantle and
> crust. "By saying it's differentiated," said Buczkowski, "we're
> basically saying Vesta was a little planet trying to happen."
>
> For more information on the paper, see
> http://www.agu.org/news/press/pr_archives/2012/2012-42.shtml .
>
> Jia-Rui C. Cook 818-354-0850
> Jet Propulsion Laboratory, Pasadena, Calif.
> jia-rui.c.cook at jpl.nasa.gov
> Sean Treacy 202-777-7516
> American Geophysical Union, Washington
> streacy at agu.org
>
> 2012-304
>
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Received on Wed 26 Sep 2012 10:58:19 PM PDT