Rev 253: Dec 15-22, 2016, Saturn, rings and Pandora Options

[Adam Hurcewicz]

Here is new photo of Pandora - 2016-12-18 21:15 (UTC)

from IR3, Green, and UV3 filters

N00273192-uv3
N00273193-ir3
N00273194-g

Attached thumbnail(s)

 

[Bjorn Jonsson]

Here is another version from the same sequence of images, i.e. an IR3-GRN-UV3 composite of Pandora. There are two versions, one with minor enhancements and another one with greatly exaggerated color to better reveal color variations. The exaggerated version probably has some minor color artifacts.

[Bjorn Jonsson]

On Twitter, Damia pointed out that the ring images are really spectacular now. As mentioned by Damia, in this image obtained on 2016-12-18 22:47 (UTC), non-parallel features are visible in the rings. As far as I know, Cassini is now obtaining the highest resolution ring images it has obtained since the hours following Saturn Orbit Insertion back in July 2004.

[Ant103]

Yeah, it astound me. I wasn't expected features like that ! It looks like some stretched material, but it's not, because it's ice and rock cobbles, dust, an everything.

Is it possible to know the resolution of this picture, x meters by pixel for example ?

[Bjorn Jonsson]

The problem is that I don't know the viewing geometry or exactly which part of the rings this image shows. But when the image was obtained Cassini was ~156,000 km from Saturn's center and the subspacecraft latitude was 33 degrees south, i.e. we are viewing the unlit side of the rings.

Assuming that Cassini was viewing the ring radial distances visible in the image at close to the highest possible resolution and that the image shows features not far from the Cassini Division the resolution should be ~500 meters/pixel. If instead this is the inner part of the B ring the resolution becomes ~600 meters/pixel.

This is a lot of 'ifs' but at least it indicates that the resolution is very likely to be better than 1 km/pixel and that it is *probably* not far from 0.5 km/pixel.

[Bjorn Jonsson]

Additional information - I decided to take a loot at the CICLOPS Looking Ahead page and found this (see http://www.ciclops.org/view/8451/Rev251-253):

After the Pandora observation, ISS will acquire a series of very high-resolution radial scans of the unlit side of Saturn's ring system. These will be the highest resolution, ISS ring observation to date. This observation will include images of the outer B ring and Cassini division, the middle A ring, and the outer A ring, including the Keeler Gap which is generated by the gravitational interaction between ring particles and the embedded small moon Daphnis.

I'm now pretty sure that the resolution of the above ring image is ~0.5 km/pixel.