'rock' satellite flybys, The next ten weeks Options

[jasedm]

Can't compare to Enceladus' close-up of course, but Cassini has a moderately close approach (non-targeted) to the moon Pallene on the 19th August, and I understand there are some planned images in the sequences.
The approach distance is just under 40,000km, although images probably won't be taken bang-on C/A.
The moon is only ~4km across, but with luck, a few shots in the order of about 15 pixels in the NAC should be possible.

The best raw images I could find to date of Pallene were taken on June 8th 2005 and the distance to target is not given. From the apparent diameter of the moon in the images though, I'm guessing range was between 50,000km and 100,000km.
Below is one of those images cropped, enhanced, and magnified x4
The speckling evident is likely artefacts of the processing rather than actual surface features, but it does show pronounced non-sphericity.

Hopefully if the sequences on Rev 81 do include Pallene, we may see a crater or two at the high phase angles

Attached thumbnail(s)

 

[Ken90000]

Did we miss Pallene? The images appear blank. I had hoped that we would see some detail on its tiny ten-pixel surface.

[tallbear]

Did we miss Pallene? The images appear blank. I had hoped that we would see some detail on its tiny ten-pixel surface.

Yes... Pallene was missed...No Live Update was performed
but it would not have mattered .... Pallene was in Eclipse .


T

[Ken90000]

Thanks, T

Perhaps there will be another opportunity later in the mission.

[jasedm]

The relevant looking-ahead article on Ciclops suggested imaging attempts whilst Pallene was in direct sunlight, so was this a pointing error, or was that part of the sequence not uploaded to the spacecraft?
Cassini flies closer (around 30,000km) on 17th October this year, but I think there is a downlink during close-approach so images are unlikely to be planned.
This means no closer images than the 2005 ones in the XM.

[Floyd]

Lots of great images of DAPHNIS--potential movie. In this image you can see Daphnis' shadow on the rings. Additional representative images 2, 3, 4. The gores seem to be drawn out of the plane and catch the sun.

[jasedm]

It seems Daphnis kicks a lot of material up out of the ringplane and into sunlight as it orbits. It certainly causes more obvious ring material disturbances than does Pan within the Encke gap.

[ugordan]

The best raw images I could find to date of Pallene were taken on June 8th 2005 and the distance to target is not given.

For what it's worth, here's that dataset in calibrated natural color, magnified 4x:

No other enhancements were done. Target distance was reported to be 76 000 km, phase angle 21 degrees. Effectively featureless surface, down to the NAC resolving power. It does appear to have a noticeable bluish tint to it, something Prometheus, Pandora and inner ring moons don't share, but Telesto does.

[Tom Tamlyn]

Will there be any opportunities for better images of Pallene in the current mission?

TTT

Edit: The three Pallene encounters listed on the Cassini site for 2009 are all further away the June 8, 2005 image (94,000 km or further).

[pat]

Will there be any opportunities for better images of Pallene in the current mission?

TTT

Edit: The three Pallene encounters listed on the Cassini site for 2009 are all further away the June 8, 2005 image (94,000 km or further).

there are no flyby observation of Pallene during 2009. The only Pallene flyby request in 2010 that is still a possibility is the one in rev 128 on DOY 79, that segment of the extended mission hasn't been integrated yet (the one in rev 130 on DOY 117 seems to be Dead Right There due to an RSS gravity pass during the Enceladus flyby)