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Posted by: DrShank Dec 13 2010, 04:23 PM

Tethys - A New Ridge

It was posted on my blog. It was posted on Facebook. Now see it here, limited engagement only!
Those topographic maps of Saturn's icy moons i showed at DPS in October show lots of cool things.
Among them an large sinuous ridge stretching diagonally across the front face of Tethys. Rising 2 to 3
kilometers, it is always ~550 km from the rim of giant crater Odysseus. On one side are smooth
textured rolling heavily cratered plains, but between the ridge and Odysseus are heavily pitted plains.
Either the ridge is a tectonic ring formed by Odysseus, like the multiring basins on the Moon and Mercury,
or it is the outer edge of a massive ejecta deposit from Odysseus. Also shown here is the enhanced color
view of the same side showing the dusky equatorial band now attributed to the bombardment of high-energy
retrograde electrons spiralling inside Saturn's magnetosphere. A similar band was discovered on Mimas,
which i will talk again about at AGU tomorrow.

Paul (-from SF)

Posted by: EDG Dec 13 2010, 06:47 PM

Nice find! Will you be posting something showing the Mimas ridge after your talk too?

Posted by: Phil Stooke Dec 13 2010, 07:29 PM

No, Mimas spectrally distinct band, not Mimas ridge!

Phil

Posted by: DrShank Dec 13 2010, 11:22 PM

phil is right. see http://stereomoons.blogspot.com/2010/10/colors-published.html for the low-down on why both satellites have this color band. kinda like a cummerbund i guess . . . Its all in the alteration of the surface microstructure by high-energy electrons. cool that they have to power to do this.

Posted by: hendric Dec 14 2010, 04:23 AM

So are you talking about the whole blue band around the middle? I thought it was a color stitching problem.

Posted by: scalbers Dec 31 2010, 10:38 PM

I think the Tethys band is real with an early mention here (posts 12 & 15):

http://www.unmannedspaceflight.com/index.php?showtopic=5093&st=0&p=114175&hl=tethys&#entry114175

This band is a separate phenomenon from the Tethys ridge.

Posted by: DrShank Jan 1 2011, 04:16 PM

Thats Correct.
Tethys and Mimas both have surface color and brightness alterations in a wide band along their equators (on the leading side only).
These are due to electron bombardment.
Tethys has a narrow topographic ridge crossing the equator that is also circumferential around the giant Odysseus basin. This might be due to ejecta deposition altho we are having some trouble replicating it on the computer. Whether Mimas has a ridge is not yet known but will be shortly. Turns out these small moons are rather more complicated . . .

Posted by: scalbers Jan 9 2011, 09:46 PM

Yes, interesting to see all these phenomena. What is it that constrains the width of the electron deposition? It looks to have a fairly well defined range of latitudes on Tethys.

Posted by: climber Jul 29 2015, 05:07 PM

Red arcs of Tethys: http://www.jpl.nasa.gov/news/news.php?feature=4671

Posted by: volcanopele Jul 29 2015, 08:34 PM

Glad the red streaks on Tethys are getting some attention. I was excited for the Rev164 encounter because it enabled high resolution imaging of some of them.