[X] My Assistant

[volcanopele]

The DPS conference in Pasadena is now in full swing (and I am not there). News and press releases are slowly trickling out of that conference, from New Scientist which reported on an Enceladus theory relating cosmic rays and Enceladus' jets and warm south polar region, to public releases at the Cassini JPL site, to glogger Brad Thomson reporting on the conference for the Planetary Society. So I thought I would create a thread just for Cassini news from this conference.

Enceladus
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There is already a thread regarding the Cooper et al. theory relating cosmic rays and the jets, so I won't touch on that here. Brad Thomson went to a few of the Enceladus talks and had a few interesting things to report. First, the ISS team is now moving away from the idea that the thrust faulting seen along the south polar terrain margin as well as the overall global tectonic pattern suggests that Enceladus experienced a flattening of its polar axis (due to an increasing in its rotation rate for example), and moving more toward a regional tectonism explaination. Again, any theory regarding the south polar terrain not only has to explain the appearance of that area, but also the tectonic pattern seen in other regions as well. Perhaps Nimmo and Pappalardo's diapir theory would work best here. The ISS team also reported on the leading hemisphere terrain. Only the western margin of this terrain has been observed at resolutions better than 1 km/pixel (that will change next year, IIRC), but what has been seen is reminiscent of the south polar region, with its criss-crossing network of ridges and troughs. Another example of a "south polar-like relic terrain" is south of Diyar and Sarandib Planitiae.

Brad also reported on talks given by John Spencer, Andy Ingersoll, and Feng Tian. John Spencer gave a plenary talk on the current state of Enceladus science on Monday. One interesting tidbit was that one of the Voyagers (I presume 2 since it came much closer to Enceladus) could have observed the tiger stripe sulci had it not been for an error that prevented the acquitition of high-resolutions of Enceladus. Would be curious to know the details on these observations (Phil?). Ingersoll examined the dynamics of the plumes and showed that some of the geysers point in directions different from normal to the surface (which of course complicates my vent location idents). Not sure about the continuous source comment. Maybe this has to do with CDA's need for a moon-wide source of dust in addition to the south polar source... Feng Tian's work on ejection velocities seem to further rule out sublimation as a plume mechanism.

Saturn
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VIMS has released an image, String of Pearls, which shows a pattern of cloud clearings in Saturn's northern hemisphere. These clearings maybe related to a large planetary wave at that latitude.

[edstrick]

Voyager 1 "saw" the tiger stripes or related terrain as higher contrast albedo markings in long range approach images that were part of a distant enceladus partial rotational coverage sequence. It's clear there there was likely to be something interesting to look at there... but no possibility of looking with Voyager's northern views during relatively close approach.