The http://saturn.jpl.nasa.gov/multimedia/products/pdfs/20071205_titan_mission_description.pdf is now up.
1,300 km altitude, southern hemisphere, outbound. ISS and VIMS will observe Ontario Lacus.
The new 'Looking Ahead' has also appeared on Ciclops. Edit - info already posted by VP, sorry.
Unusually close-up ISS view of Ontario Lacus may have some smear. Looking forward to it all the same!
All...
been eagerly awaiting these south polar passes. I believe most of the cloud activity that was so prevalent in 2004 has abated at the pole. Wonder what VIMS and ISS will see there now.
Also be neat to see what VIMS and ISS make out for Ontario Lacus... can VIMS pin done a liquid phase for the dark material? From the sample snapshots looks like CIRS will try for a temperature reading.
And I think T39 (December 20th) has RADAR SAR over the southern hemisphere.
Great Holiday treats on the way!!!!!
Craig
The T38 flyby is now the top story on the Cassini website. You might notice a disconnect between the description the header images uses, "Cassini's Search for Subsurface Ocean Continues," and the goals of the flyby: to image Ontario Lacus. Originally, the T38 encounter was to be a "gravity pass", with the Radio Science team having time at closest approach and at other times in the encounter to measure the gravitational field of Titan. Combined with three other passes in the nominal mission, the interior structure and the thickness of Titan's internal ocean could be discerned. After the discovery of Ontario Lacus, it became important to determine whether it was in fact a lake filled with liquid methane. Cassini's trajectory during T38 takes it directly over Ontario Lacus. The VIMS team successfully argued for a change in the T38 sequence to make it an ORS pass, giving prime targeting control to VIMS during C/A. However, many internal documents have not been updated to reflect that change (including my copy of the timeline, as you can tell from the CICLOPS looking ahead page, which still mentions the non-C/A RSS passes).
Which might explain why the graphic used on the Cassini homepage says that this pass will continue the search for an internal ocean.
Could somebody dispel a little bit of my ignorance? Why is it that VIMS can do imaging at closest approach (less that 2000 km.) while ISS images taken closer than 40,000 km are 'often smeared'?
VIMS has a much lower spacial resolution per pixel.
Thanks paxdan. Presumably also there is no way to 'stop down' the ISS camera so that it can take smaller detailed shots at closer ranges of things like the Huygens landing site and lake shores?
VP - it wasnt just the VIMS team.
One of your ISS colleagues close to me was also among the chorus (including myself) that
argued for T38 being used for ISS and VIMS to observe Ontario, it being a particularly good
opportunity to do so. (Radar will hit it in XM, hopefully with both SAR and altimetry - the illumination
will be poorer then, but we dont need no stinkin sunshine...).
A major factor in this re-assignment was the calculation (once all the
details of ground station availability etc. were in and the error correlation matrices calculated) was that
the incremental value of the flyby towards the gravity field (and tidal variation thereof) determination
was in fact rather small. RSS will get better results from T45 in XM (assuming XM gets approved)
raws seem to be appearing at this very minute
Indeed. More than 500 within the last hour it seems! Many, many beautiful details here. I didn't spot Ontario Lacus on my first skim through though. Anybody else find it? BTW what happens if they post more than 500 in one go? Does that mean that some aren't viewable?
On closer inspection I notice that this was taken from approximately the right distance:
http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=137342
It doesn't quite jump out, does it?
Let's hope VIMS has done better. The whole lake couldn't possibly be obscured by cloud, could it?
Anyhow there's a real feast of other stuff, like this:
http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=137126
-and lots of fantastic mosaicry to be done no doubt.
Lotsa nice pictures for our mosaic masters out there.
Some more multiple-breached crater features in?: http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS35/N00098412
(Multiple-breached = eroded, cracked, breached, used, abused, infilled, and collapsed.)
Just experimenting, not claiming any kind of insight or worth above or beyond my own enjoyment
Mosaic of narrow angle images, taken from 50 000 - 75 000 km:
The multi-ringed structure of that presumed impact crater seems clearer in these new images. I expect good science to flow from this regarding the thickness and other physical properties of the solid ice crust and what lies beneath.
Has anyone been able to discern Ontario Lacus from the Raws?
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