Explanation: What's creating those dark bands on Saturn? Sometimes it takes a little sleuthing to figure out the how and why of a picture taken by the Saturn-orbiting Cassini spacecraft. Let's see. That large orb on the left must be Saturn itself. Those arcs on the right are surely the rings. The dark band running diagonally must be the shadow of Saturn on the rings. That leaves the unusual dark bands superposed on Saturn's disk -- are they the shadows of the rings? A punctilious detective would conclude that they are not. If one looks carefully, the rings arc from behind the planet on the lower left, around to the right, and therefore must pass on the camera side of the planet on the upper left. So the rings themselves cause the dark streaks on Saturn. These rings segments appear dark because they are in the shadow of Saturn. The night part of Saturn shows a faint glow because of sunlight reflected from other parts of the rings. Got it? Unfortunately, if it weren't for the tile floor, tomorrow's picture would be even harder to understand.
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Tue Oct 12, 2010 11:29 am
by orin stepanek
from the links: this is neat!
Click to play embedded YouTube video.
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Tue Oct 12, 2010 1:43 pm
by biddie67
Good Grief!! I don't "got" it - yet. Will have to come back when I have more time ....
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Tue Oct 12, 2010 3:21 pm
by emc
I like that this APOD was taken in visible light… not as common for an APOD. I also like the M.C. Escher feel this image has even though it’s a real physical perspective from Cassini.
I thought this detail from the ISS credit link was cool… 103 people acknowledged for the actual building and testing of the Cassini Imaging Science System.
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Tue Oct 12, 2010 4:21 pm
by Stephen Benham
Probably a simple question for those in the know, but there are three irregular white patches (due to disturbed particles?). Why are they all in what looks like the same ring? Are there not 'shepherds' in every groove, so wouldn't you expect to see more irregular patches? Or could this be a groove in the process of being formed by a comparatively recently introduced shepherd? Thanks.
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Tue Oct 12, 2010 4:42 pm
by bystander
biddie67 wrote:Good Grief!! I don't "got" it - yet. Will have to come back when I have more time ....
The Bad Astronomer gives a pretty good explanation at the link Got it.
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Tue Oct 12, 2010 5:40 pm
by Boomer12k
Always reminds me of the old record albums. Saturn's Rings must play a lot of songs!
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Wed Oct 13, 2010 7:15 am
by yaari
Have to rotate the image 180 degrees and then everything is clear.
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)
Posted: Wed Oct 13, 2010 7:29 pm
by biddie67
I got it!! Thanks, bystander!!!!!
Re: APOD: Saturn: Light, Dark, and Strange (2010 Oct 12)