Enceladus August 11, 2008 encounter, Close-up observations of plume vents Options

[Floyd]

Just 8 days until the next Enceladus encounter.

CICLOPS Rev 80 Looking Ahead will appear here soon.

Cassini Enceladus 080EN Mission Description is here now.

We get to fly through the south polar jets again.

-Floyd

[edit] Soon = somtime before encounter

[ElkGroveDan]

Yikes they are really going to be diving trough those ice plumes. Makes me wonder if a post encounter view of Saturn might look something like this:

Attached thumbnail(s)

 

[jmknapp]

Yikes they are really going to be diving trough those ice plumes.

I just made an animation of the encounter (60MB MPG file, right-click on image below to download):



It's from the point of view if the ISS narrow-angle camera, using pointing & position info from the SPICE kernels--pretty frenetic panning around at times! For a lot of the approach the camera looks to be pointing out into space--maybe towards where the plumes are located?

[nprev]

Let me be the first to say both "OOO!!!" and "AHHH!"....damn cool!!!!

Doug will probably dislike your chosen background music, but he'll get over it... Really beautiful work, man; absolutely inspiring. Thank you for sharing it with us!

[jasedm]

Joe that's an inspirational piece of work! - many thanks for sharing it with us.
Am I right in concluding that the sequence planners may have allowed for some saturnshine exposures on the outbound leg?
I think the camera pointing into space is a consequence of other instruments being 'prime' during the very closest approach, in order to get other data on the plumes themselves.
Can't wait for the results on this one.

[jmknapp]

Joe that's an inspirational piece of work! - many thanks for sharing it with us.

My pleasure... and thanks to Cassini for timely updating of the SPICE navigation data, allowing such looks into the future.

Am I right in concluding that the sequence planners may have allowed for some saturnshine exposures on the outbound leg?
I think the camera pointing into space is a consequence of other instruments being 'prime' during the very closest approach, in order to get other data on the plumes themselves.
Can't wait for the results on this one.

Don't know about specific plans. The team does publish such info sometimes in their "science plan" SPICE files, but the current plan, S42, ends on August 11 (hours before the Enceladus flyby ) and the next plan, S43, hasn't been posted yet. Usually there's a several day gap between the end of one plan and the posting of the next.

Maybe the links Floyd gave in the first post will tell some more, when updated.

[ynyralmaen]

I think the camera pointing into space is a consequence of other instruments being 'prime' ...

That may well be true, but I suspect it may also be related to the rapid motion of Enceladus across the sky as seen from Cassini during such a low altitude encounter... the spacecraft can't turn quickly enough to track the surface during the entire encounter, so before closest approach, the attitude is set ready to image the south pole, with the remote sensing instruments pointing north. The south pole is then in the field of view as soon as possible, yielding the highest resolution images.

[ilbasso]

I imagine they also want to avoid exposing the camera to a high-speed encounter with particles in the plumes.

[tallbear]

Enceladus is in eclipse from 224-21:42 to 225-00:08 --- T

[jmknapp]

Enceladus is in eclipse from 224-21:42 to 225-00:08 --- T

Note to self: figure out how to model eclipses sometime. Saturn's oblateness makes it even harder than otherwise.

[Decepticon]

Is there any chance for Saturn Shine imaging during this encounter?

[volcanopele]

There is some chance. But keep in mind that the sub-solar point is pretty close to the sub-Saturn point during the encounter, so areas illuminated by Saturn would also be illuminated by the Sun.

During the eclipse, well, you'd be seeing the same areas we would be seeing immediately before the eclipse starts, at good resolution, in sunlight.

[Floyd]

Link to map of Enceladus encounters on Emily's What's up in the solar system for week of August 4

[jmknapp]

Looking at the planned ISS pointing during the encounter in more detail, it looks like there is a long dwell time on the Cairo tiger stripe, vent 'E':



Any particular reason to concentrate on that one? One interesting thing is that it's exactly on the day/night terminator at the time of the observation (the green square shows the NAC view):

[nprev]

Any particular reason to concentrate on that one?

Might've answered your own question in your post. Bet they're looking for some high-phase optical plume pics.