[X] My Assistant

[Bjorn Jonsson]

Cassini has previously imaged the unlit side of the rings but now it is doing extensive observations of the unlit side. For the first time in its mission Cassini is spending a significant amount of time north of the ringplane - earlier it has done so only near periapsis but this orbit is different.

This is a quick RGB composite I did from wide angle images:



I made no attempts to correct the color - this is probably not very far from the true color of the rings. Large color variations are apparent, the C ring and the Cassini division appear much more bluish than the thicker rings (A and B ). It should be noted that these images were very probably downliked with the 12 -> 8 bit encoding which basically means that dark areas appear too bright in this image because I did not correct for this.

It's also interesting to compare this image to Voyager images:

Voyager 1: http://photojournal.jpl.nasa.gov/catalog/PIA02241

Voyager 2: http://photojournal.jpl.nasa.gov/catalog/PIA01955
Voyager 2: http://photojournal.jpl.nasa.gov/catalog/PIA01389

[alan]

Speaking of high phase angles, according to Solar System Simulator on September 15 Cassini will be pass through Saturn's shadow while at a distance of 2.163 million miles.
http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
I wonder what observations are planned for this.

[ugordan]

I wonder what observations are planned for this.

From an imaging standpoint, it looks like a very nice opportunity for a wide angle mosaic. 3 footprints ought to cover the width of the scene so it wouldn't be too expensive to acquire a multicolor set.
Earth should be visible as well -- if it's not drowned out by forward scattered light from the rings. This will be a very high phase angle situation so it's possible the E and G rings will stand out very nicely. The main rings (at least the C and F rings) might be brilliant as well.
Looking forward to it.

[Bjorn Jonsson]

The occultation lasts about 15 hours so there should be plenty of time to point the RSP towards Saturn without accidentally pointing it at the Sun. Sure looks like an interesting imaging opportunity.

The following animation showing the occultation starts at 2006-09-15 03:00:00 UTC and spans a period of 24 hours. The field of view is 8 degrees.

 sun_occult.avi ( 1.3MB ) Number of downloads: 568