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Fraser
2006-May-06, 03:50 AM
SUMMARY: When they first noticed the dark equatorial regions on Titan, researchers thought they could be looking at oceans of liquid methane. But new radar images taken by NASA's Cassini spacecraft has provided the answer: sand dunes. The images show enormous dunes that run parallel to each other for hundreds of kilometers. Saturn's powerful gravity causes gentle winds on Titan, possibly transporting sand from across the moon and depositing it around the equator.

View full article (http://www.universetoday.com/am/publish/ua_titan_seas.html)
What do you think about this story? post your comments below.

galacsi
2006-May-06, 11:49 AM
we need a Rover on Titan and a serious one with great autonomy to probe this extraordinary planet (moon !).

zephyr46
2006-May-07, 03:58 AM
Crossed with a Tauntaun (http://en.wiki/Taun-Taun).

:-)

Well it is still an ocean of a different phase of matter.

antoniseb
2006-May-07, 09:30 AM
we need a Rover on Titan and a serious one with great autonomy to probe this extraordinary planet (moon !).

I think the current talk (no actual proposed missions) is about a blimp, not a wheeled rover. The blimp should have the ability to go to ground level and collect samples and do microscopic imaging. Titan's heavy atmosphere makes this a useful way to do close up work.

Jerry
2006-May-08, 01:30 PM
Since no one seems to have a clue what the sand is made out of (even though it is as red as sand of Mars, and has the refractive index, the permeability and emissivity of silicates), it makes much more sense to get on our hands and knees with a Mossbaur than it does to float around and wonder...

antoniseb
2006-May-08, 01:52 PM
The blimp/balloon missions, as I'd mentioned above, are being designed with the ability to go to th surface and collect samples. They won't just float around and wonder.

galacsi
2006-May-08, 08:32 PM
Since no one seems to have a clue what the sand is made out of (even though it is as red as sand of Mars, and has the refractive index, the permeability and emissivity of silicates), it makes much more sense to get on our hands and knees with a Mossbaur than it does to float around and wonder...

Wow ! and if they look like , have the refractive index, the permeability and emissivity of silicates ; may be they are silicates !

But the planet is much too light to be a silicate only body . So an ice body with a coat of silicates ? Quite strange ! Or the Gravity dont work as usual on Titan ?
Stranger and stranger !

So we need a Rover or a Blimp (I am not a sectarian) , fast !

Jerry
2006-May-11, 01:07 AM
Titan flyby T14 will primarily be a bistatic radar pass: Cassini will turn all her transmitters on and scream at the moon while big ears listen on the earth:

http://www.aas.org/publications/baas/v32n3/dps2000/121.htm

"Information regarding surface properties is recovered from analysis of the received echo intensity, polarization, and spectral properties. In particular, echo polarization over the Brewster-angle-range of icy surfaces (50-65 deg.) yields direct estimates of the (composite) surface dielectric constant independent of surface roughness (if surface scattering is dominant)."

A quick trip to the dielectric tables should give a very good feel for how sandy the sand is. Water-ice should have tale-a-tale reflection. Ok, it is never that simple, but there are already strong indications from Cassini's active radar that the surface is not water-dominated.