Dawn's Survey Orbit at Ceres Options

[climber]

when Dawn gets down to the Mapping Orbits.

--Bill

She was supposed to start on July 15th but was kind enough to let NH show happen.
Do you all realise that we have now exploring 3 active worlds at the same Time?
Go Dawn, go NH, go Rosetta (and wake up Philae).

[DFinfrock]

Climber, Mars is active too.
Global dust storms, dust devils, lower-speed wind transport and erosion, gully features in some craters, sublimation and deposition of CO2 in polar terrain, just to mention a few.

[Bill Harris]

And Cassini.

[climber]

Climber, Mars is active too.
Global dust storms, dust devils, lower-speed wind transport and erosion, gully features in some craters, sublimation and deposition of CO2 in polar terrain, just to mention a few.

You're right...but not as active as UNMSF those weeks

[ZLD]

Well this is exciting. 'Active' is an interesting world choice. Does sublimation get counted as an active event in all cases? I would say that if a low velocity, icy impactor were to leave fractured chunks and began sublimating away, this would not constitute an active event. However, if the sublimation is present within the surface and is modifying the terrain, this could be then considered an active event.

Four big questions pop out at me with this news:

-If Occator is a location for active sublimation, where did the ice come from?

-If Occator is a location for active sublimation, with hundreds of larger and smaller white spots that may be related, why is Occator possibly the only active region among them?

-If Occator is a location for active sublimation, what role does the white material play in the sublimation?

-If Occator is a location for active sublimation, does local or global transport exist?

Really wish we were getting the same type of regular science updates with Dawn that we have been getting with NH. Dawn is just as interesting but the teams public outreach efforts seem to be night and day almost.

[Bill Harris]

It has to be more complex than just ice and sublimation.

--Bill

[dvandorn]

All right, so, if they are seeing hazes over Occator at mid-day, where are the images that show this phenomenon? Will they be embargoed until someone can have a paper published about it?

-the other Doug

[wildespace]

Hmm, could it be underground salty water rising to the surface and evaporating, leaving the bright salt deposits?

[ZLD]

I tried cleaning up the projected image of Occator.

Will they be embargoed until someone can have a paper published about it?

It seems this way from the lack of scientific news coming from the mission.

[ugordan]

The Chris Russell talk is now available here (hat tip to nasaspaceflight.com user leovinus)

[ZLD]

A while back I posted a highly processed closeup of Occator. Here is a much updated, reprocessed version of that, overlayed with the projected image.






(click to animate)

Ok, so if this method holds any water (haha...) I'm seeing what could be multiple cryovolcanoes near the brightest spot. It still isn't clear why there is other multiple much brighter spots. It would be exceedingly useful if the team could take another fast shutter image so the nature of the thin wispy streaks, could be determined (plumes or lava).

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Edit
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Here is another blink with the source data.


(click to animate)

Really looks like theres a caldera near the upper right that has some kind of wispy trail that may be up away from the surface. Not sure what we would exactly be looking for in a sublimation event on a body like Ceres but this looks like a good chunk of shiny ice in this pit.

[Habukaz]

The Chris Russell talk is now available here (hat tip to nasaspaceflight.com user leovinus)

So Russell actually suggests the haze could be caused by sublimation ("largest comet in the asteroid belt"); but also says the bright spots were not created by impacts? Getting a bit confusing.

[Guest_Steve5304_*]

Any news on hamo. When do we expect the first survey?

[Bill Harris]

I'm starting my work in the Ceres Spots, beginning with Spot 5, Occator Crater:

https://univ.smugmug.com/Dawn-Mission/Ceres...t5-Enh-d-X2.png

It will be interesting to see this resolved during the HAMO and LAMO phases of the mission. This is much akin to the TLPs (Transient Lunar Phenomena) studied in the '60's which were as controversial as the impact vs volcanic origins of lunar craters.

Info:
https://en.wikipedia.org/wiki/Transient_lunar_phenomenon

or Google "transient lunar phenomena" or "aristarchus lights" for more. Warning, it gets strange.

--Bill

[Herobrine]

While we're waiting for HAMO, I thought I'd make a preview of what we can expect to see at HAMO and LAMO.
At the top are 3 frames from the survey orbit (originally 1024x1024). The middle row shows the spots from the frame above at their HAMO-equivalent scale. The bottom row shows the same spots at their LAMO-equivalent scale.

All images are shown at 25% actual image size.
_{I feel like this may have already been done before, and I didn't check through the forum, so my apologies if this is redundant.}