Dawn approaches Vesta, Approach phase, 3 May to 16 July 2011 Options

[dilo]

I did further sharpening in addition to gamma/contrast adjustment:

As I suspected from previous images (and as highlighted by Phil) patches of smoother (recent?) terrain are confirmed, especially in some regions around equator, while craterizations inside the super-crater around south pole seems higher...

[Phil Stooke]

"It looks a bit like Epimetheus' South pole"

Fran - you are right. I think that's exactly what we see at Epimetheus.

Phil

[machi]

I have no words! It's so different world! Vesta looks like some hybrid between Hyperion and Enceladus.
Even south crater doesn't looks like crater (is it really crater?).
And smooth areas on asteroid of size of the Mimas! Really extraordinary.

[tasp]

I guess I am a little fuzzy on formation of center peaks. Isn't the slumping of the walls and compressing the center regions of the 'hole' what mounds up the peak?

How does this work when the impactor is big enough to blow the crater walls plumb off the asteroid entirely? Or are we seeing 'core' swelling into the 'wound'?


Amazing something this weird and wonderful is already apparent, this is going to be a fun goomer to be looking over for the next year.

[Phil Stooke]

No, slumping of the walls is not involved. It's compression of the surface under the impact followed by rebound.

Phil

[Juramike]

Cool-o animation of a crater formation sequence (Done for a terrestrial impact):
http://upload.wikimedia.org/wikipedia/comm...b-animation.gif

[siravan]

My quick guestimate of the height of the center peak based on its shape and shadow is around 36 km above the crater plain. This is one huge mountain!

[Guest_Sunspot_*]

My quick guestimate of the height of the center peak based on its shape and shadow is around 36 km above the crater plain.

That's going to look good closeup

[volcanopele]

"It looks a bit like Epimetheus' South pole"

Fran - you are right. I think that's exactly what we see at Epimetheus.

Phil

Helene and its north polar crater is another great example.

While people process the newly released image, again keep in mind that it has been magnified from the original. I've attached a de-magnified version (looks like the released version is 4x the raw data).

Attached image(s)

 

[nprev]

I wonder if that central peak contains not only mantle stuff, but also some core stuff. THIS is gonna be interesting!

[tasp]

Cool, maybe the core is swelling into the 'wound'.
Wonder what Vesta looks like 180 degrees around, like maybe Mercurian chaotic terrain . . .

[Steve G]

I'm astonished by the lack of cratering. This is truly a different personality. I'm looking forward to getting to know her!

[Mr Valiant]

Astonishing. It's gunna be one hell of a ride. For some reason, I can't get my eyes around the
appearence of the 'crater' as a mountain. I guess the small body size and resulting
perculiar lighting contribute to the illusion. Wish I had a handfull of playdough, I sure like
to check out this ambiguity.

[Gsnorgathon]

The mountain is just the central peak. The impact structure as a whole is nearly as big across (~460km) as Vesta's diameter (~530km). In some respects, it's not really a crater or a basin, because it's convex. (Though perhaps not with respect to the gravity gradient - just one more cool thing to find out!)

I'm guessing the smoothness means the impact happened semi-recently (so maybe it's only 3 billion years old, instead of 4...), and great swaths of Vesta are covered by bits that were formerly on the interior.

[Gladstoner]

The smoothness struck me too as odd. Perhaps Vesta was once sheathed in a layer of ice as is Ceres (assuming such ice is indeed present) that was fully or partially removed by the effects of the massive impact, along with the former, cratered surface.

Also, I am quite intrigued by the apparent ridge extending from the mountain. Any ideas (guesses) how such a feature could form, assuming it isn't an artifact due to the low resolution?