HAMO, (aka High Altitude Mapping Orbit) Options

[DrShank]

The spiral pattern is mostly a map projection effect. One of our team has located them and they fit great circles.

[dilo]

We will keep you posted.

Thanks pablo!

[alan]

The spiral pattern is mostly a map projection effect. One of our team has located them and they fit great circles.

Sounds like they are due to the impacts of orbiting debris.

[Phil Stooke]

On Iapetus, that process is called on to create a ridge... can it do both?

Phil

[stevesliva]

Sounds like they are due to the impacts of orbiting debris.

If you watch the replay of the presentation that I linked to above, they mention that they are wide, flat-bottomed with steep sides. Certainly don't sound like crater chains. The also believe the ages of the equatorial ones correspond to the Rheasilvia impact and the northern ones to the older southern basin.

[DrShank]

Impact debris here would form radial or spiral from the center. These are extension cracks formed from several possible sources. Examples include shape change and reorientation. Among others. It's proving difficult to get the exact ages however and we have some numerical models yet to test. Should be interesting!

[Sarunia]

Vesta in almost natural colors (filters centered at 440, 650 and 750 nm).
Two basic images:

English captions and 5 other versions are here.
Original raw images are available here.

Wow ! Great work, and thank you for the raw. How did you get these ?

[machi]

I haven't much informations about this, I know only, that it's from anonymous source in the Dawn team and it was one-time thing, so we must
wait now for another (raw) data until official release (~ end of year 2012).

[Sarunia]

I haven't much informations about this, I know only, that it's from anonymous source in the Dawn team and it was one-time thing, so we must
wait now for another (raw) data until official release (~ end of year 2012).

Ok. Thanks Machi.

[dilo]

As probably you noticed in the simulator, starting from yesterday Dawn ignited engines and started spiraling toward LAMO:

Edit: I updated the plot with last data...

[Stefan]

I haven't much informations about this, I know only, that it's from anonymous source in the Dawn team and it was one-time thing, so we must
wait now for another (raw) data until official release (~ end of year 2012).

Hi Machi,

Our "raw" FC images are certainly not in 8 bit PNG format and we don't produce them in Photoshop, so what you obtained from this anonymous source cannot be described as raw. You had to work with what you had, and you did a fine job producing those color images, but it is beyond me how Emily can present your images on her blog as "nearly natural color".

Stefan.

[machi]

Hi Stefan

"Our "raw" FC images are certainly not in 8 bit PNG format and we don't produce them in Photoshop,
so what you obtained from this anonymous source cannot be described as raw"

Yes, I wrote this inaccurately. What I wanted to write is, that this kind of images
(directly derived from real raw images, with some basic informations about them,
which allow this kind of processing), will not be available until next year.
All published images are without these informations, or they are strongly derived.

"You had to work with what you had, and you did a fine job producing those color images"

Thanks!

"but it is beyond me how Emily can present your images on her blog as "nearly natural color""

Because source images are not in appropriate spectral bands and even more, I have no idea, if these are calibrated or not,
I don't know exactly how close to "natural" these images are. Some published spectra looks flat for Vesta (in visible),
so I tried similar settings for final images.
For now, few images in "natural" colors was published (here) , so
direct comparison is possible (btw these images are using red on 700 nm).

ADMIN FORMATTING EDIT

[dilo]

Engines cut-off few hours ago, around 530 km height... probably thrust will resume soon:

Attached thumbnail(s)

 

[Floyd]

What is the target altitude for LAMO? Edit found it:180 km. That low to get gravity field. See Marc Rayman's December 10, 2010 post on the Dawn Jornal

[dilo]

Further update, showing in grey periods with engines off (with very indicative start/end times):

Based on a private comunication from Dr Rayman, these thrust interruptions will become more frequent while descending in Vesta's gravity field; main purpose is to re-orient spacecraft in order to transmit radiometric data and establish/transmit new thrust profile.

Edit: updated to Nov,7 18:00 UTC - new engine stop lasting 21 hrs, up to now!