Rev 213, February 26th to March 28th Options

[jasedm]

Details for the next Cassini revolution are now available here. This orbit includes yet another ring occultation, high-res observations of the F-ring, studies of the environment between the inner D-ring and Saturn's cloud tops (proximal orbits anyone?), and a nice Titan flyby focussing primarily on atmosphere and temperature gradients. Also featured, a final glimpse of Iapetus, with a ~1,000,000km flyby which should improve cartography of the northern regions a little. The Iapetus observations are at a similar range to the best Voyager 2 images of that moon, but with a much better camera - the flyby should fill some gaps at medium resolution in the north polar areas.

Much to look forward to!

[remcook]

Nice clump + spirals in the F-ring http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=326202

[jasedm]

Yes, huge amounts of activity in the F-ring - that's a gigantic clump!

Lovely image of a crescent Pandora too:

Attached thumbnail(s)

 

[jasedm]

Incidentally, there seems to be a large moonlet, or clump of material right at the core of the F-ring in the latest raws.

I don't have the tools to do an mpeg, but images N00236275 to N00236279 show it moving with the ring. It's darker than the ring-material, as it appears to be in the foreground. I'm pretty sure it's not an artifact.

Below is one of the images, with the 'moonlet' highlighted

Attached thumbnail(s)

 

[Astro0]

I'm liking the Saturn- or Ring-shine on Pandora's "dark side".

[Ian R]

Fitting that these were taken on the Ides of March, given that Prometheus looks like a dagger blade here:

[jasedm]

Further to my post above suggesting a moonlet or clump in the vicinity of the F ring, I'm wondering if this is S/2004 S6, a discovery made just after Cassini arrived in the Saturn system.

It's size was constrained at a maximum of ~5km, but it was not recovered in later searches.

The object is certainly raising a wake in the F-ring as it orbits, so must have appreciable mass. It must also be very strongly perturbed by both Prometheus and Pandora, making its orbital mechanics difficult to pin down.

[Phil Stooke]

Some descriptions of these things suggest they form as loose collections of material, dissipate and reform, so it may not really be the same object at all.

Phil

[jasedm]

There's definitely a huge amount of dynamism in and around the F-ring. Perhaps there is a basic 'core' of material to this moonlet (clump) that is fairly constant, but which sheds and re-accretes material as it is shunted, somewhat like a pinball through the core of the F-ring by Prometheus and Pandora, accounting for the 'braiding' which has been apparent since we have been able to observe it (i.e .early-eighties Voyager imagery).

If there's one example of this, then there are likely others too - perhaps a number of transient clumps exist, at various points around the F-ring.

This is activity on a scale of years and decades, rather than millennia/aeons, and might explain the observed activity better than as has been suggested, recent impacts onto the F-ring.

The F-ring orbits towards the end of the mission will no doubt give us a better insight into these processes.

[ngunn]

Anybody know what's going on with the raw images at the the Cassini website? In recent weeks 'search raw images' has not been working and now on the latest few pages there are no images at all, only filenames or placemarkers (whatever the right term is).

[elakdawalla]

Nope. I just sent an email to Alice Wessen.

[Floyd]

Carolyn Porco is going to San Francisco to head up some new projects, so there may be changes in who oversees the image pipeline?

[ngunn]

I just sent an email to Alice Wessen.

Thanks! It seems to be back in full working order.

[MarcF]

And finally, the North Pole of Iapetus. For the first time, craters Roland and Tibbald are fully illuminated. Turgis and Falsaron basins are also visible.
An additional basin in Roncevaux Terra seems also confirmed (upper right).

http://saturn.jpl.nasa.gov/multimedia/imag...8/N00236614.jpg

Regards,
Marc.

[scalbers]

Indeed, here is how the new image fits into my previous map:



The blinking animation has two frames:

1) New image on top of Voyager map

2) My previous map with Cassini and Voyager