Dawn Survey Orbit Phase, First orbital phase Options

[tasp]

Love the "asteroid size comparison poster", amazing to see all the suspects in a police lineup style poster, and LOL, I gets my 1 pixel Itakowa comparison!

[antipode]

I can't wait to see...errrr...the antipode of that crater! Mega chaotic terrain?

P

[Gladstoner]

Also, mass wasting from the crater sides does not seem to explain the 5-km-ish spaced parallel ridges on the crater floor. I'm wondering if they are ridges of olivine....

They could be pressure ridges between adjacent debris flows.

[Gladstoner]

A little bit of Vesta on Mars?:

[attachment=24854:MarsRA_sm.jpg]

And on Earth?:

[attachment=24855:eastspringcomp.png]

(Double Spring landslide complex, Oregon)

I had a heck of a time finding a decent example of a terrestrial landslide to compare to Vesta. If the grooved terrain is indeed a system of debris flows, they may turn out to be the finest example of the process anywhere in the Solar System.

[centsworth_II]

I was intrigued by the quick look Cassini got at the conical craters of Saturn's Phoebe. Now it looks like we'll get a much better look at the same sort of crater on Vesta. The images below are very roughly to the same scale. Although Vesta is a little more than twice the diameter of phoebe, the craters in question seem to be about the same size on both bodies.

[centsworth_II]

For somewhat not geologically-minded, what is reminding all of you about Miranda? I don't see the similarities really...

From The Planetary Society Blog:
"The interior of that south polar basin sure looks weird. All around the central peak are chevron-shaped ridgy features that bring to mind Miranda -- which, by the way, is very similar in size to Vesta."

[Drkskywxlt]

From The Planetary Society Blog:
"The interior of that south polar basin sure looks weird. All around the central peak are chevron-shaped ridgy features that bring to mind Miranda -- which, by the way, is very similar in size to Vesta."

Yeah...I guess I can see that. To me (again, not a geologist), it just all looks like grooves similar to those on other small bodies like Phobos and Lutetia.

[Stefan]

OK this is making me absolutely crazy. Another image release (yay!) but as with all the previous image releases the reported scale is wrong. They keep reporting the pixel scale for the original, unenlarged image, and then they post an image that has been enlarged (badly) by some non-integer factor and fail to divide the pixel scale by whatever their enlargement factor was.

The last few images were enlarged by an integer factor. Did you find something wrong with how they were enlarged?

While the quoted pixel scale is indeed not valid for the enlarged image, it is the relevant number for knowing the smallest detail that can be resolved.

[centsworth_II]

...it just all looks like grooves...

All groves are not alike. There are straight grooves, sinuous groves, grooves with right angles.

[Stefan]

Congrats to the Dawn team for a successful orbit insertion! Now looking forward to a color image of Vesta...

There is a false color image on the MPS Dawn page (click the latest headline).

[MahFL]

The focus is getting better.
The Clangers definetly live there.

[Steve G]

The south polar crater is, by appearances, a flat slice right across the south pole. However, gravity is always pulling towards the center of the body. So on the outer limits of this flat massive basin, it is gravitationally speaking, an up hill slope. This would naturally draw the loose surface material towards the center of the crater, and perhaps create the cracks and rifts, would it not?

[algorimancer]

Was arrival facing the south polar crater planned, or a coincidence of orbital mechanics and intent to enter a polar orbit? I understand that it is a target of interest, just wondering about the extent of the planning process in that regard.

[Juramike]

Coordinated views of the normal and contrast-enhanced IR composite of 4 Vesta
(lineup is approximate) note the 4-pack of craters to the N in both images.

[Phil Stooke]

Nice one, Mike.

The orange spot in the false color view coincides with the darker spot seen in distant views, including the 'crater with tails' as someone described it, on the edge of the smooth patch we saw a while ago.

Phil