Starship Asterisk*

Chris Peterson wrote:

owlice wrote:Moon shadows on Saturn typically appear inky black, just as the shadows of the rings do. I don't know what the spot is -- maybe a camera or processing artifact -- but it appears far too light to me to be a moon shadow.

7205_17346_1p.jpg

I assume we're talking about the circular structure below the rings, towards the lower pole? It's just a storm system. The same system shows up in other images made around the same time, such as the one here taken a couple of weeks later.

owlice wrote:Moon shadows on Saturn typically appear inky black, just as the shadows of the rings do. I don't know what the spot is -- maybe a camera or processing artifact -- but it appears far too light to me to be a moon shadow.

Beyond wrote:I think that hint may be a little too subtle.

neufer wrote: http://asterisk.apod.com/viewtopic.php?t=30256#p188364

http://asterisk.apod.com/viewtopic.php?f=29&t=30256 wrote:
Even Saturn's rings appear to dwarf Tethys (660 miles, or 1,062 kilometers across), which is in the upper left of the image, although scientists believe the moon to be many times more massive than the entire ring system combined.

Boomer12k wrote:

RedFishBlueFish wrote:The black & white brings out what appears to at least one crater on Saturn.
This seems odd, as I did not think that the surface of the planet was visible.

It is either a cloud structure, if you look closely up above it, you also see some WHITER spots, or it could be a camera artifact. I am thinking an asteroid, would have a blackish ring or mark around it, like Jupiter did.

RedFishBlueFish wrote:The black & white brings out what appears to at least one crater on Saturn.

This seems odd, as I did not think that the surface of the planet was visible.

As the dawn of this New Year's Eve brings METAR 311053Z 10006KT 2SM -DZ BR OVC003 10/10 A3006 it looks as though I might have time to find out a bit more, as won't be going outside.

Happy New Year All!

Ray-Optics wrote:
RedFishBlueFish: I wondered about that too. It can't be a crater. It almost looks like an asteroid impact only a few hours old. I'm surprised it wasn't mentioned by the editor.

Ray-Optics wrote:Yes, we see sunlight on Saturn's face. Imagine you're Saturn and you're wearing a broad-brimmed hat. You pull the hat down against the sunlight. Now, are you looking at the dark side of the brim? Yes.

bay area john wrote:So... it seems the rings are directly over the equator of Saturn... or are they? If so, is that to be expected of ring systems, part of the tidal forces that keep them suspended? Actual Moons don't seem to be so constrained to a single specific plane, do they?

Cassini FAQ wrote: Why do Saturn's rings all lie in the same plane? Why are planetary rings always found in their equatorial planes and not sometimes crossing their poles?

Saturn, its rings, and most of its moons all probably formed from a spinning disk of gas and dust within the original solar nebula. As it collapsed toward its center, it would have formed a central sphere (which became Saturn), leaving a disk of material orbiting its equator. That material probably coalesced into many or most of Saturn's moons. The ring particles may be material that was left over from this process, or they may be the remnants of a moon that was shattered by collision or by tidal forces (see Roche limit). In either case, the ring particles would have kept the angular momentum of the original disk, and continued orbiting Saturn in its equatorial plane.

bay area john wrote:So... it seems the rings are directly over the equator of Saturn... or are they? If so, is that to be expected of ring systems, part of the tidal forces that keep them suspended? Actual Moons don't seem to be so constrained to a single specific plane, do they?

owlice wrote:Just "alright"??

:: passes out cold ::