HAMO, (aka High Altitude Mapping Orbit) Options

[ilbasso]

My total ignorance of geology is showing, but I could imagine a scenario in which the southern basin impact partially melted the entire surface of Vesta, with the asteroid "ringing" seismically for a while afterward. The concentric grooves in Phil's polar projection remind me of waves that froze as the surface cools.

Again, I am not a geologist...just relaying the impression that I get from that projection.

[SolarSystemRubbl...]

Yes, here's the latest Dawn journal:

http://dawn.jpl.nasa.gov/mission/journal_09_27_11.asp

[Gsnorgathon]

My total ignorance of geology is showing, but I could imagine a scenario in which the southern basin impact partially melted the entire surface of Vesta...
(snip)

Two things: 1) a good deal of the ejecta from the impact might have been molten, so you wouldn't need to melt the whole surface. Just melt some of it and then spray it all over the place. 2) You don't necessarily need anything molten. Seismic shaking from an impact that large on a body that small would be huge. Get some nice resonances going, pile a bunch of fresh ejecta on it, and poof! Troughs and ridges. Sound waves frozen in stone.

[machi]

Two new stereoscopic images from my blog:
South polar mountain - crosseye pair, anaglyph and blog entry.

[dilo]

Two new stereoscopic images from my blog:

Beautiful!

[antipode]

Wow, what an extraordinary structure that has turned out to be!

P

[Hungry4info]

Is this the first image from HAMO?
Looks splendid either way!

[volcanopele]

This image was released yesterday:

http://dawn.jpl.nasa.gov/multimedia/dawn_v...pping_orbit.asp

It has a slightly lower pixel scale at 65 meters per pixel.

[dilo]

Indeed, while yesterday's published image was snapped on Sept,17 from 750km height (based on resolution and according to simulator data), the Volcanopele highlighted one was probably taken the following day, when Dawn reached nominal HAMO height, slightly below 700 km.

[dilo]

One question: do someone knows updated Vesta size after Dawn exploration?
I guess even preliminary estimates are a lot better than Hubble-based figures but, strangely, I cannot find anything else! (obviously, I am referring to average ellipsoidal 3 axes value)

[belleraphon1]

From the EPSC-DPS Joint Meeting 2011 ..
Media release
Dawn at Vesta: Massive mountains, rough surface, and old-young dichotomy in hemispheres
http://www.europlanet-eu.org/outreach/inde...2&Itemid=41


"NASA’s Dawn mission, which has been orbiting Vesta since mid-July, has revealed that the asteroid’s southern hemisphere boasts one of the largest mountains in the Solar System. Other results show that Vesta’s surface, viewed at different wavelengths, has striking diversity in its composition particularly around craters. The surface appears to be much rougher than most asteroids in the main asteroid belt. Preliminary results from crater age dates indicate that areas in the southern hemisphere are as young as 1-2 billion years old, much younger than areas in the north. The findings are being presented today at the EPSC-DPS Joint Meeting 2011 in Nantes, France"

This brieifing was webcast live at 6:15am Eastern U.S. and I missed the first 30 minutes.

Good stuff!

Craig

[volcanopele]

As mentioned in the press release, several names have been approved by the IAU for features that provide the names for mapping quadrants on Vesta. Here is a map identifying those craters (and one hill) :

[ElkGroveDan]

One question: do someone knows updated Vesta size after Dawn exploration?

As always, Emily has the answer:

http://www.planetary.org/blog/article/00003207/

[Phil Stooke]

... or part of the answer. She doesn't give the three axes.

Phil

[dilo]

Thanks for highlight, ElkGroveDan! And perfect timing, Emily!
Obviously, in the report volume exponent is missed (should be 7,532E+7 cubic km); average radius uncertain should be 850 m.