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Dawn's Survey Orbit at Ceres
Bill Harris
post Aug 1 2015, 02:50 AM
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I am working on a "Poster Session" presentation of the geomorphology of Ceres. This is a work-in-progress and new images are up at:

https://univ.smugmug.com/Dawn-Mission/Ceres...geomorph-v1.jpg

--Bill


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Habukaz
post Aug 1 2015, 01:05 PM
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A new Dawn Journal is out: http://dawnblog.jpl.nasa.gov/2015/07/29/da...ournal-july-29/

The next observing campaign will begin on 17 August.


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Bill Harris
post Aug 6 2015, 07:19 AM
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And of course, imagery from the Survey Orbit continues to be posted. It is up to image "SO-41", with Zadini Crater.

http://photojournal.jpl.nasa.gov/catalog/PIA19614

--Bill


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ZLD
post Aug 6 2015, 01:56 PM
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Looks like they just posted the a few of the CG slides from the presentation previously mentioned.





And an animation with the increased relief.


And lastly, a news piece on the Dawn website about the Occator image and animation. There is brief mention that the spots probably aren't ice and they may be salt related but otherwise, the piece is lacking in any new science details.


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Bill Harris
post Aug 6 2015, 02:33 PM
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Along with SO-42. SO-43 SO-44 SO-45 SO-46 SO-47 SO-48 SO-49 SO-50 SO-51 SO-52 SO-53 now SO-54.


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Bill Harris
post Aug 17 2015, 06:52 PM
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And the Dawn team has produced a cylindrical projection map with feature names:

http://photojournal.jpl.nasa.gov/catalog/PIA19625

and the mission is now in the HAMO phase. Wow.

--Bill


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kap
post Aug 20 2015, 04:48 AM
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Does the equator look less cratered in the map because of the way the map is stretched, or is there actually a band across the equatorial area that has fewer craters than other areas?
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JohnVV
post Aug 20 2015, 05:45 AM
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QUOTE (kap @ Aug 20 2015, 12:48 AM) *
Does the equator look less cratered in the map because of the way the map is stretched, or is there actually a band across the equatorial area that has fewer craters than other areas?


that looks to be caused by the highpass used to remove the middle frequency data and even the look out

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Malmer
post Aug 20 2015, 09:14 AM
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The light is hitting the surface from zenith along the equator. that makes the craters much less visible. the further north/south you go the more relief is seen due to the sun angle.

here is a good reference on much of an effect the sun angle makes:
http://www.lroc.asu.edu/featured_sites/view_site/6
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Bill Harris
post Aug 20 2015, 12:56 PM
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It's a byproduct of the distortion from the mapping projection and how the individual Dawn photos are selected and placed on the map. North of the equator shadows are on the south sides of the craters ("sun to the south") and the Sun become lower (shadows longer) towards the North polar area. And vice versa to the South. On or near the Equator the craters have little or no shadow and the Sun is near local "Noon". Consequently at or near the Equator the craters are de-emphasized and that band looks "flat and featureless".

In a manner of thinking, you have a sphere and you're trying to squish it onto a flat surface and have things on it look uniform-- a mapmaker's conundrum.

--Bill


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Sean
post Jul 28 2017, 02:13 PM
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Click thru for a video showing Ceres relief...



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Explorer1
post Sep 27 2017, 06:31 PM
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Happy 10th "launchiversary", Dawn! And to think it nearly didn't happened.

Looks like it's still in the 30 day long orbit doing cosmic ray measurements; not much in the way of new imagery these days.

And from the latest Dawn journal:
QUOTE
Before the end of the year, NASA will formulate another new set of objectives that will take it to the end of its operational life.

Hmm...
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monty python
post Sep 28 2017, 06:31 AM
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I think the most amazing statistic from the Dawn journal is that the ion engines have imparted almost as much delta v as the the rocket that launched it!
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Explorer1
post Oct 20 2017, 12:34 AM
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Mission extension approved!
Trying to get as low as 200 km, through perihelion in 2018!
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TheAnt
post Oct 20 2017, 02:01 PM
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Now there be a chance to get the data hoped from the lower orbit they decided against. -due to the faulty gyroscopes
So Dawn seem intent on doing the finals with the highest grade possible, with a hunt for water, vapor and better resolution images.
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