Friday, June 24, 2005

New Pan Image: Revealing Pan's Influence

CICLOPS has released this view of Saturn's innermost satellite Pan, a small moon that orbits within the Encke Gap of the A ring. The gravitational effects of Pan create density waves within the A ring, as seen in the two images shown above. In addition, several ringlets reside within the Encke Gap. The most prominent is seen in the top image. Kinks in this ringlet are reminscient of those seen in the F ring. One possible explanation for these kinks is that Pan isn't the only moonlet in the Encke Gap.

Thursday, June 23, 2005

Raw Images of the Day

Rendered view of the Huygens landing site region

Rene Pascal, as he posted in the comments on the Topography article, has put on the web a series of rendered views of Titan's surface using his mosaics and our current understanding of the structure of Titan's atmosphere. These views were created Povray and show how Titan's atmosphere affects the view of the sky above and the surface below as you decend through the atmosphere. Very nice images. Almost wish they were a little bigger so I can turn some of them in to desktop wallpaper.

New Rhea Image: Rhea's Memory

CICLOPS has released this view of Rhea's leading hemisphere (the large crater at the 3:30 position is likely Djuli, I think...). As you can see from this image, taken from a distance of 1.4 million km on May 5 with a resolution of 9 km/pixel, Rhea is a heavily cratered world with nowhere the level of tectonic resurfacing as on Enceladus or even Dione. Given its ancient surface, Rhea could hold the key to understand the impactor population throughout the history of Saturn system where worlds like Enceladus have completely wiped clean the earliest craters.

Tuesday, June 21, 2005

New Cassini Image: Aligned Moons

CICLOPS has released this view of Dione and Enceladus as seen from Cassini on May 5, 2005, when Cassini was just a tenth of a degree above the ring plane. Visible on the right hand side of the image is the limb of the night side of Saturn (you can see the rings eclipsed by Saturn on the far side). Here you can see Dione's leading hemisphere, complete with ridges in the northern hemisphere (seen at higher resolution near the eastern limb in December), as well as a 350-km wide impact basin in the southern hemisphere (seen at higher resolution a few weeks ago).

And yes, Phil, I know the caption says, "as is a large impact basin (not seen in NASA Voyager spacecraft images) near the moon's south pole." Had I read you abstract from 2002 when this caption was being written last month, I would have put in a comment about it.

Monday, June 20, 2005

Huygens Topography

The DISR team has released an animation showing the topography near the Huygens landing site. The topography was derived from DEM-models created by using stereo observations of various regions on the surface of Titan as Huygens descended. The area shown above, topography from the movie on the left, a frame from Huygens on the right for context, shows the "shoreline"region observed by Huygens. You can see that the dark material near the bottom of the frame is definitely lower in altitude than the bright terrain. In addition, there appears to be a cliff associated with the dark channel near the top of the DEM model. Topography within the bright material is a bit hard to interpret but it is obvious that the topography and the morphology of the dendritic channels indicate flow from bottom to top, away from the "shoreline".

It should be emphasized that all the features seen in Huygens images are SURFACE features. Not fogs. Not clouds. Not giant animals. Surface features. I know people have occasional seen features move on the surface or features look like waves, but so far nothing has indicated standing liquid from the spectra or surface analyses.

Raw Images of the Week

Haven't had to do this in a while: Raw images of the week:
For those interested in Saturn, there is also a enormous selection of Saturn images just begging to be mosaicked. Not by me, I'm not a gas giant person, but I'm sure someone our there will give it a try ;)