Did you see this? It's an artist's conception of how gravity from the tiny moon Daphnis creates ripples in Saturn's rings - created by Kevin Gill of NASA.
This image was pretty popular here, and elsewhere on the web - but people often don't come out and say from the start that it's not a photo. The actual photos are less beautiful but... hey, they're real! And the ripples look different in the photos. Let's take a look.
(1/n)
This 2005 photo, taken by the Cassini probe, was the first time anyone actually saw Saturn's moon Daphnis! It's only 8 kilometers across.
This gap in Saturn's A ring was first discovered by Voyager, and it was named the Keeler Gap. It's 35 kilometers wide. I guess this gap let people guess the existence of a moon, and later the ripples in the A ring let people guess where the moon must be! I don't really know the history here.
(2/n)
There's a larger gap in the A ring called the Encke cap, created by a larger moon called Pan, which you can see clearly here.
To the left you see the smaller Keeler gap. If you look very closely you can see the ripples near the Keeler gap... and if you look *very* closely you can see, or at least imagine, the moon Daphnis.
(3/n)
John Carlos Baez
Neo Ehproque
